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Data Collection – Methods Types and Examples

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Data collection

Data Collection

Definition:

Data collection is the process of gathering and collecting information from various sources to analyze and make informed decisions based on the data collected. This can involve various methods, such as surveys, interviews, experiments, and observation.

In order for data collection to be effective, it is important to have a clear understanding of what data is needed and what the purpose of the data collection is. This can involve identifying the population or sample being studied, determining the variables to be measured, and selecting appropriate methods for collecting and recording data.

Types of Data Collection

Types of Data Collection are as follows:

Primary Data Collection

Primary data collection is the process of gathering original and firsthand information directly from the source or target population. This type of data collection involves collecting data that has not been previously gathered, recorded, or published. Primary data can be collected through various methods such as surveys, interviews, observations, experiments, and focus groups. The data collected is usually specific to the research question or objective and can provide valuable insights that cannot be obtained from secondary data sources. Primary data collection is often used in market research, social research, and scientific research.

Secondary Data Collection

Secondary data collection is the process of gathering information from existing sources that have already been collected and analyzed by someone else, rather than conducting new research to collect primary data. Secondary data can be collected from various sources, such as published reports, books, journals, newspapers, websites, government publications, and other documents.

Qualitative Data Collection

Qualitative data collection is used to gather non-numerical data such as opinions, experiences, perceptions, and feelings, through techniques such as interviews, focus groups, observations, and document analysis. It seeks to understand the deeper meaning and context of a phenomenon or situation and is often used in social sciences, psychology, and humanities. Qualitative data collection methods allow for a more in-depth and holistic exploration of research questions and can provide rich and nuanced insights into human behavior and experiences.

Quantitative Data Collection

Quantitative data collection is a used to gather numerical data that can be analyzed using statistical methods. This data is typically collected through surveys, experiments, and other structured data collection methods. Quantitative data collection seeks to quantify and measure variables, such as behaviors, attitudes, and opinions, in a systematic and objective way. This data is often used to test hypotheses, identify patterns, and establish correlations between variables. Quantitative data collection methods allow for precise measurement and generalization of findings to a larger population. It is commonly used in fields such as economics, psychology, and natural sciences.

Data Collection Methods

Data Collection Methods are as follows:

Surveys involve asking questions to a sample of individuals or organizations to collect data. Surveys can be conducted in person, over the phone, or online.

Interviews involve a one-on-one conversation between the interviewer and the respondent. Interviews can be structured or unstructured and can be conducted in person or over the phone.

Focus Groups

Focus groups are group discussions that are moderated by a facilitator. Focus groups are used to collect qualitative data on a specific topic.

Observation

Observation involves watching and recording the behavior of people, objects, or events in their natural setting. Observation can be done overtly or covertly, depending on the research question.

Experiments

Experiments involve manipulating one or more variables and observing the effect on another variable. Experiments are commonly used in scientific research.

Case Studies

Case studies involve in-depth analysis of a single individual, organization, or event. Case studies are used to gain detailed information about a specific phenomenon.

Secondary Data Analysis

Secondary data analysis involves using existing data that was collected for another purpose. Secondary data can come from various sources, such as government agencies, academic institutions, or private companies.

How to Collect Data

The following are some steps to consider when collecting data:

  • Define the objective : Before you start collecting data, you need to define the objective of the study. This will help you determine what data you need to collect and how to collect it.
  • Identify the data sources : Identify the sources of data that will help you achieve your objective. These sources can be primary sources, such as surveys, interviews, and observations, or secondary sources, such as books, articles, and databases.
  • Determine the data collection method : Once you have identified the data sources, you need to determine the data collection method. This could be through online surveys, phone interviews, or face-to-face meetings.
  • Develop a data collection plan : Develop a plan that outlines the steps you will take to collect the data. This plan should include the timeline, the tools and equipment needed, and the personnel involved.
  • Test the data collection process: Before you start collecting data, test the data collection process to ensure that it is effective and efficient.
  • Collect the data: Collect the data according to the plan you developed in step 4. Make sure you record the data accurately and consistently.
  • Analyze the data: Once you have collected the data, analyze it to draw conclusions and make recommendations.
  • Report the findings: Report the findings of your data analysis to the relevant stakeholders. This could be in the form of a report, a presentation, or a publication.
  • Monitor and evaluate the data collection process: After the data collection process is complete, monitor and evaluate the process to identify areas for improvement in future data collection efforts.
  • Ensure data quality: Ensure that the collected data is of high quality and free from errors. This can be achieved by validating the data for accuracy, completeness, and consistency.
  • Maintain data security: Ensure that the collected data is secure and protected from unauthorized access or disclosure. This can be achieved by implementing data security protocols and using secure storage and transmission methods.
  • Follow ethical considerations: Follow ethical considerations when collecting data, such as obtaining informed consent from participants, protecting their privacy and confidentiality, and ensuring that the research does not cause harm to participants.
  • Use appropriate data analysis methods : Use appropriate data analysis methods based on the type of data collected and the research objectives. This could include statistical analysis, qualitative analysis, or a combination of both.
  • Record and store data properly: Record and store the collected data properly, in a structured and organized format. This will make it easier to retrieve and use the data in future research or analysis.
  • Collaborate with other stakeholders : Collaborate with other stakeholders, such as colleagues, experts, or community members, to ensure that the data collected is relevant and useful for the intended purpose.

Applications of Data Collection

Data collection methods are widely used in different fields, including social sciences, healthcare, business, education, and more. Here are some examples of how data collection methods are used in different fields:

  • Social sciences : Social scientists often use surveys, questionnaires, and interviews to collect data from individuals or groups. They may also use observation to collect data on social behaviors and interactions. This data is often used to study topics such as human behavior, attitudes, and beliefs.
  • Healthcare : Data collection methods are used in healthcare to monitor patient health and track treatment outcomes. Electronic health records and medical charts are commonly used to collect data on patients’ medical history, diagnoses, and treatments. Researchers may also use clinical trials and surveys to collect data on the effectiveness of different treatments.
  • Business : Businesses use data collection methods to gather information on consumer behavior, market trends, and competitor activity. They may collect data through customer surveys, sales reports, and market research studies. This data is used to inform business decisions, develop marketing strategies, and improve products and services.
  • Education : In education, data collection methods are used to assess student performance and measure the effectiveness of teaching methods. Standardized tests, quizzes, and exams are commonly used to collect data on student learning outcomes. Teachers may also use classroom observation and student feedback to gather data on teaching effectiveness.
  • Agriculture : Farmers use data collection methods to monitor crop growth and health. Sensors and remote sensing technology can be used to collect data on soil moisture, temperature, and nutrient levels. This data is used to optimize crop yields and minimize waste.
  • Environmental sciences : Environmental scientists use data collection methods to monitor air and water quality, track climate patterns, and measure the impact of human activity on the environment. They may use sensors, satellite imagery, and laboratory analysis to collect data on environmental factors.
  • Transportation : Transportation companies use data collection methods to track vehicle performance, optimize routes, and improve safety. GPS systems, on-board sensors, and other tracking technologies are used to collect data on vehicle speed, fuel consumption, and driver behavior.

Examples of Data Collection

Examples of Data Collection are as follows:

  • Traffic Monitoring: Cities collect real-time data on traffic patterns and congestion through sensors on roads and cameras at intersections. This information can be used to optimize traffic flow and improve safety.
  • Social Media Monitoring : Companies can collect real-time data on social media platforms such as Twitter and Facebook to monitor their brand reputation, track customer sentiment, and respond to customer inquiries and complaints in real-time.
  • Weather Monitoring: Weather agencies collect real-time data on temperature, humidity, air pressure, and precipitation through weather stations and satellites. This information is used to provide accurate weather forecasts and warnings.
  • Stock Market Monitoring : Financial institutions collect real-time data on stock prices, trading volumes, and other market indicators to make informed investment decisions and respond to market fluctuations in real-time.
  • Health Monitoring : Medical devices such as wearable fitness trackers and smartwatches can collect real-time data on a person’s heart rate, blood pressure, and other vital signs. This information can be used to monitor health conditions and detect early warning signs of health issues.

Purpose of Data Collection

The purpose of data collection can vary depending on the context and goals of the study, but generally, it serves to:

  • Provide information: Data collection provides information about a particular phenomenon or behavior that can be used to better understand it.
  • Measure progress : Data collection can be used to measure the effectiveness of interventions or programs designed to address a particular issue or problem.
  • Support decision-making : Data collection provides decision-makers with evidence-based information that can be used to inform policies, strategies, and actions.
  • Identify trends : Data collection can help identify trends and patterns over time that may indicate changes in behaviors or outcomes.
  • Monitor and evaluate : Data collection can be used to monitor and evaluate the implementation and impact of policies, programs, and initiatives.

When to use Data Collection

Data collection is used when there is a need to gather information or data on a specific topic or phenomenon. It is typically used in research, evaluation, and monitoring and is important for making informed decisions and improving outcomes.

Data collection is particularly useful in the following scenarios:

  • Research : When conducting research, data collection is used to gather information on variables of interest to answer research questions and test hypotheses.
  • Evaluation : Data collection is used in program evaluation to assess the effectiveness of programs or interventions, and to identify areas for improvement.
  • Monitoring : Data collection is used in monitoring to track progress towards achieving goals or targets, and to identify any areas that require attention.
  • Decision-making: Data collection is used to provide decision-makers with information that can be used to inform policies, strategies, and actions.
  • Quality improvement : Data collection is used in quality improvement efforts to identify areas where improvements can be made and to measure progress towards achieving goals.

Characteristics of Data Collection

Data collection can be characterized by several important characteristics that help to ensure the quality and accuracy of the data gathered. These characteristics include:

  • Validity : Validity refers to the accuracy and relevance of the data collected in relation to the research question or objective.
  • Reliability : Reliability refers to the consistency and stability of the data collection process, ensuring that the results obtained are consistent over time and across different contexts.
  • Objectivity : Objectivity refers to the impartiality of the data collection process, ensuring that the data collected is not influenced by the biases or personal opinions of the data collector.
  • Precision : Precision refers to the degree of accuracy and detail in the data collected, ensuring that the data is specific and accurate enough to answer the research question or objective.
  • Timeliness : Timeliness refers to the efficiency and speed with which the data is collected, ensuring that the data is collected in a timely manner to meet the needs of the research or evaluation.
  • Ethical considerations : Ethical considerations refer to the ethical principles that must be followed when collecting data, such as ensuring confidentiality and obtaining informed consent from participants.

Advantages of Data Collection

There are several advantages of data collection that make it an important process in research, evaluation, and monitoring. These advantages include:

  • Better decision-making : Data collection provides decision-makers with evidence-based information that can be used to inform policies, strategies, and actions, leading to better decision-making.
  • Improved understanding: Data collection helps to improve our understanding of a particular phenomenon or behavior by providing empirical evidence that can be analyzed and interpreted.
  • Evaluation of interventions: Data collection is essential in evaluating the effectiveness of interventions or programs designed to address a particular issue or problem.
  • Identifying trends and patterns: Data collection can help identify trends and patterns over time that may indicate changes in behaviors or outcomes.
  • Increased accountability: Data collection increases accountability by providing evidence that can be used to monitor and evaluate the implementation and impact of policies, programs, and initiatives.
  • Validation of theories: Data collection can be used to test hypotheses and validate theories, leading to a better understanding of the phenomenon being studied.
  • Improved quality: Data collection is used in quality improvement efforts to identify areas where improvements can be made and to measure progress towards achieving goals.

Limitations of Data Collection

While data collection has several advantages, it also has some limitations that must be considered. These limitations include:

  • Bias : Data collection can be influenced by the biases and personal opinions of the data collector, which can lead to inaccurate or misleading results.
  • Sampling bias : Data collection may not be representative of the entire population, resulting in sampling bias and inaccurate results.
  • Cost : Data collection can be expensive and time-consuming, particularly for large-scale studies.
  • Limited scope: Data collection is limited to the variables being measured, which may not capture the entire picture or context of the phenomenon being studied.
  • Ethical considerations : Data collection must follow ethical principles to protect the rights and confidentiality of the participants, which can limit the type of data that can be collected.
  • Data quality issues: Data collection may result in data quality issues such as missing or incomplete data, measurement errors, and inconsistencies.
  • Limited generalizability : Data collection may not be generalizable to other contexts or populations, limiting the generalizability of the findings.

About the author

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Muhammad Hassan

Researcher, Academic Writer, Web developer

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Data collection in research: Your complete guide

Last updated

31 January 2023

Reviewed by

Cathy Heath

Short on time? Get an AI generated summary of this article instead

In the late 16th century, Francis Bacon coined the phrase "knowledge is power," which implies that knowledge is a powerful force, like physical strength. In the 21st century, knowledge in the form of data is unquestionably powerful.

But data isn't something you just have - you need to collect it. This means utilizing a data collection process and turning the collected data into knowledge that you can leverage into a successful strategy for your business or organization.

Believe it or not, there's more to data collection than just conducting a Google search. In this complete guide, we shine a spotlight on data collection, outlining what it is, types of data collection methods, common challenges in data collection, data collection techniques, and the steps involved in data collection.

Analyze all your data in one place

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  • What is data collection?

There are two specific data collection techniques: primary and secondary data collection. Primary data collection is the process of gathering data directly from sources. It's often considered the most reliable data collection method, as researchers can collect information directly from respondents.

Secondary data collection is data that has already been collected by someone else and is readily available. This data is usually less expensive and quicker to obtain than primary data.

  • What are the different methods of data collection?

There are several data collection methods, which can be either manual or automated. Manual data collection involves collecting data manually, typically with pen and paper, while computerized data collection involves using software to collect data from online sources, such as social media, website data, transaction data, etc. 

Here are the five most popular methods of data collection:

Surveys are a very popular method of data collection that organizations can use to gather information from many people. Researchers can conduct multi-mode surveys that reach respondents in different ways, including in person, by mail, over the phone, or online.

As a method of data collection, surveys have several advantages. For instance, they are relatively quick and easy to administer, you can be flexible in what you ask, and they can be tailored to collect data on various topics or from certain demographics.

However, surveys also have several disadvantages. For instance, they can be expensive to administer, and the results may not represent the population as a whole. Additionally, survey data can be challenging to interpret. It may also be subject to bias if the questions are not well-designed or if the sample of people surveyed is not representative of the population of interest.

Interviews are a common method of collecting data in social science research. You can conduct interviews in person, over the phone, or even via email or online chat.

Interviews are a great way to collect qualitative and quantitative data . Qualitative interviews are likely your best option if you need to collect detailed information about your subjects' experiences or opinions. If you need to collect more generalized data about your subjects' demographics or attitudes, then quantitative interviews may be a better option.

Interviews are relatively quick and very flexible, allowing you to ask follow-up questions and explore topics in more depth. The downside is that interviews can be time-consuming and expensive due to the amount of information to be analyzed. They are also prone to bias, as both the interviewer and the respondent may have certain expectations or preconceptions that may influence the data.

Direct observation

Observation is a direct way of collecting data. It can be structured (with a specific protocol to follow) or unstructured (simply observing without a particular plan).

Organizations and businesses use observation as a data collection method to gather information about their target market, customers, or competition. Businesses can learn about consumer behavior, preferences, and trends by observing people using their products or service.

There are two types of observation: participatory and non-participatory. In participatory observation, the researcher is actively involved in the observed activities. This type of observation is used in ethnographic research , where the researcher wants to understand a group's culture and social norms. Non-participatory observation is when researchers observe from a distance and do not interact with the people or environment they are studying.

There are several advantages to using observation as a data collection method. It can provide insights that may not be apparent through other methods, such as surveys or interviews. Researchers can also observe behavior in a natural setting, which can provide a more accurate picture of what people do and how and why they behave in a certain context.

There are some disadvantages to using observation as a method of data collection. It can be time-consuming, intrusive, and expensive to observe people for extended periods. Observations can also be tainted if the researcher is not careful to avoid personal biases or preconceptions.

Automated data collection

Business applications and websites are increasingly collecting data electronically to improve the user experience or for marketing purposes.

There are a few different ways that organizations can collect data automatically. One way is through cookies, which are small pieces of data stored on a user's computer. They track a user's browsing history and activity on a site, measuring levels of engagement with a business’s products or services, for example.

Another way organizations can collect data automatically is through web beacons. Web beacons are small images embedded on a web page to track a user's activity.

Finally, organizations can also collect data through mobile apps, which can track user location, device information, and app usage. This data can be used to improve the user experience and for marketing purposes.

Automated data collection is a valuable tool for businesses, helping improve the user experience or target marketing efforts. Businesses should aim to be transparent about how they collect and use this data.

Sourcing data through information service providers

Organizations need to be able to collect data from a variety of sources, including social media, weblogs, and sensors. The process to do this and then use the data for action needs to be efficient, targeted, and meaningful.

In the era of big data, organizations are increasingly turning to information service providers (ISPs) and other external data sources to help them collect data to make crucial decisions. 

Information service providers help organizations collect data by offering personalized services that suit the specific needs of the organizations. These services can include data collection, analysis, management, and reporting. By partnering with an ISP, organizations can gain access to the newest technology and tools to help them to gather and manage data more effectively.

There are also several tools and techniques that organizations can use to collect data from external sources, such as web scraping, which collects data from websites, and data mining, which involves using algorithms to extract data from large data sets. 

Organizations can also use APIs (application programming interface) to collect data from external sources. APIs allow organizations to access data stored in another system and share and integrate it into their own systems.

Finally, organizations can also use manual methods to collect data from external sources. This can involve contacting companies or individuals directly to request data, by using the right tools and methods to get the insights they need.

  • What are common challenges in data collection?

There are many challenges that researchers face when collecting data. Here are five common examples:

Big data environments

Data collection can be a challenge in big data environments for several reasons. It can be located in different places, such as archives, libraries, or online. The sheer volume of data can also make it difficult to identify the most relevant data sets.

Second, the complexity of data sets can make it challenging to extract the desired information. Third, the distributed nature of big data environments can make it difficult to collect data promptly and efficiently.

Therefore it is important to have a well-designed data collection strategy to consider the specific needs of the organization and what data sets are the most relevant. Alongside this, consideration should be made regarding the tools and resources available to support data collection and protect it from unintended use.

Data bias is a common challenge in data collection. It occurs when data is collected from a sample that is not representative of the population of interest. 

There are different types of data bias, but some common ones include selection bias, self-selection bias, and response bias. Selection bias can occur when the collected data does not represent the population being studied. For example, if a study only includes data from people who volunteer to participate, that data may not represent the general population.

Self-selection bias can also occur when people self-select into a study, such as by taking part only if they think they will benefit from it. Response bias happens when people respond in a way that is not honest or accurate, such as by only answering questions that make them look good. 

These types of data bias present a challenge because they can lead to inaccurate results and conclusions about behaviors, perceptions, and trends. Data bias can be avoided by identifying potential sources or themes of bias and setting guidelines for eliminating them.

Lack of quality assurance processes

One of the biggest challenges in data collection is the lack of quality assurance processes. This can lead to several problems, including incorrect data, missing data, and inconsistencies between data sets.

Quality assurance is important because there are many data sources, and each source may have different levels of quality or corruption. There are also different ways of collecting data, and data quality may vary depending on the method used. 

There are several ways to improve quality assurance in data collection. These include developing clear and consistent goals and guidelines for data collection, implementing quality control measures, using standardized procedures, and employing data validation techniques. By taking these steps, you can ensure that your data is of adequate quality to inform decision-making.

Limited access to data

Another challenge in data collection is limited access to data. This can be due to several reasons, including privacy concerns, the sensitive nature of the data, security concerns, or simply the fact that data is not readily available.

Legal and compliance regulations

Most countries have regulations governing how data can be collected, used, and stored. In some cases, data collected in one country may not be used in another. This means gaining a global perspective can be a challenge. 

For example, if a company is required to comply with the EU General Data Protection Regulation (GDPR), it may not be able to collect data from individuals in the EU without their explicit consent. This can make it difficult to collect data from a target audience.

Legal and compliance regulations can be complex, and it's important to ensure that all data collected is done so in a way that complies with the relevant regulations.

  • What are the key steps in the data collection process?

There are five steps involved in the data collection process. They are:

1. Decide what data you want to gather

Have a clear understanding of the questions you are asking, and then consider where the answers might lie and how you might obtain them. This saves time and resources by avoiding the collection of irrelevant data, and helps maintain the quality of your datasets. 

2. Establish a deadline for data collection

Establishing a deadline for data collection helps you avoid collecting too much data, which can be costly and time-consuming to analyze. It also allows you to plan for data analysis and prompt interpretation. Finally, it helps you meet your research goals and objectives and allows you to move forward.

3. Select a data collection approach

The data collection approach you choose will depend on different factors, including the type of data you need, available resources, and the project timeline. For instance, if you need qualitative data, you might choose a focus group or interview methodology. If you need quantitative data , then a survey or observational study may be the most appropriate form of collection.

4. Gather information

When collecting data for your business, identify your business goals first. Once you know what you want to achieve, you can start collecting data to reach those goals. The most important thing is to ensure that the data you collect is reliable and valid. Otherwise, any decisions you make using the data could result in a negative outcome for your business.

5. Examine the information and apply your findings

As a researcher, it's important to examine the data you're collecting and analyzing before you apply your findings. This is because data can be misleading, leading to inaccurate conclusions. Ask yourself whether it is what you are expecting? Is it similar to other datasets you have looked at? 

There are many scientific ways to examine data, but some common methods include:

looking at the distribution of data points

examining the relationships between variables

looking for outliers

By taking the time to examine your data and noticing any patterns, strange or otherwise, you can avoid making mistakes that could invalidate your research.

  • How qualitative analysis software streamlines the data collection process

Knowledge derived from data does indeed carry power. However, if you don't convert the knowledge into action, it will remain a resource of unexploited energy and wasted potential.

Luckily, data collection tools enable organizations to streamline their data collection and analysis processes and leverage the derived knowledge to grow their businesses. For instance, qualitative analysis software can be highly advantageous in data collection by streamlining the process, making it more efficient and less time-consuming.

Secondly, qualitative analysis software provides a structure for data collection and analysis, ensuring that data is of high quality. It can also help to uncover patterns and relationships that would otherwise be difficult to discern. Moreover, you can use it to replace more expensive data collection methods, such as focus groups or surveys.

Overall, qualitative analysis software can be valuable for any researcher looking to collect and analyze data. By increasing efficiency, improving data quality, and providing greater insights, qualitative software can help to make the research process much more efficient and effective.

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Chapter 5: collecting data.

Tianjing Li, Julian PT Higgins, Jonathan J Deeks

Key Points:

  • Systematic reviews have studies, rather than reports, as the unit of interest, and so multiple reports of the same study need to be identified and linked together before or after data extraction.
  • Because of the increasing availability of data sources (e.g. trials registers, regulatory documents, clinical study reports), review authors should decide on which sources may contain the most useful information for the review, and have a plan to resolve discrepancies if information is inconsistent across sources.
  • Review authors are encouraged to develop outlines of tables and figures that will appear in the review to facilitate the design of data collection forms. The key to successful data collection is to construct easy-to-use forms and collect sufficient and unambiguous data that faithfully represent the source in a structured and organized manner.
  • Effort should be made to identify data needed for meta-analyses, which often need to be calculated or converted from data reported in diverse formats.
  • Data should be collected and archived in a form that allows future access and data sharing.

Cite this chapter as: Li T, Higgins JPT, Deeks JJ (editors). Chapter 5: Collecting data. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.4 (updated August 2023). Cochrane, 2023. Available from www.training.cochrane.org/handbook .

5.1 Introduction

Systematic reviews aim to identify all studies that are relevant to their research questions and to synthesize data about the design, risk of bias, and results of those studies. Consequently, the findings of a systematic review depend critically on decisions relating to which data from these studies are presented and analysed. Data collected for systematic reviews should be accurate, complete, and accessible for future updates of the review and for data sharing. Methods used for these decisions must be transparent; they should be chosen to minimize biases and human error. Here we describe approaches that should be used in systematic reviews for collecting data, including extraction of data directly from journal articles and other reports of studies.

5.2 Sources of data

Studies are reported in a range of sources which are detailed later. As discussed in Section 5.2.1 , it is important to link together multiple reports of the same study. The relative strengths and weaknesses of each type of source are discussed in Section 5.2.2 . For guidance on searching for and selecting reports of studies, refer to Chapter 4 .

Journal articles are the source of the majority of data included in systematic reviews. Note that a study can be reported in multiple journal articles, each focusing on some aspect of the study (e.g. design, main results, and other results).

Conference abstracts are commonly available. However, the information presented in conference abstracts is highly variable in reliability, accuracy, and level of detail (Li et al 2017).

Errata and letters can be important sources of information about studies, including critical weaknesses and retractions, and review authors should examine these if they are identified (see MECIR Box 5.2.a ).

Trials registers (e.g. ClinicalTrials.gov) catalogue trials that have been planned or started, and have become an important data source for identifying trials, for comparing published outcomes and results with those planned, and for obtaining efficacy and safety data that are not available elsewhere (Ross et al 2009, Jones et al 2015, Baudard et al 2017).

Clinical study reports (CSRs) contain unabridged and comprehensive descriptions of the clinical problem, design, conduct and results of clinical trials, following a structure and content guidance prescribed by the International Conference on Harmonisation (ICH 1995). To obtain marketing approval of drugs and biologics for a specific indication, pharmaceutical companies submit CSRs and other required materials to regulatory authorities. Because CSRs also incorporate tables and figures, with appendices containing the protocol, statistical analysis plan, sample case report forms, and patient data listings (including narratives of all serious adverse events), they can be thousands of pages in length. CSRs often contain more data about trial methods and results than any other single data source (Mayo-Wilson et al 2018). CSRs are often difficult to access, and are usually not publicly available. Review authors could request CSRs from the European Medicines Agency (Davis and Miller 2017). The US Food and Drug and Administration had historically avoided releasing CSRs but launched a pilot programme in 2018 whereby selected portions of CSRs for new drug applications were posted on the agency’s website. Many CSRs are obtained through unsealed litigation documents, repositories (e.g. clinicalstudydatarequest.com ), and other open data and data-sharing channels (e.g. The Yale University Open Data Access Project) (Doshi et al 2013, Wieland et al 2014, Mayo-Wilson et al 2018)).

Regulatory reviews such as those available from the US Food and Drug Administration or European Medicines Agency provide useful information about trials of drugs, biologics, and medical devices submitted by manufacturers for marketing approval (Turner 2013). These documents are summaries of CSRs and related documents, prepared by agency staff as part of the process of approving the products for marketing, after reanalysing the original trial data. Regulatory reviews often are available only for the first approved use of an intervention and not for later applications (although review authors may request those documents, which are usually brief). Using regulatory reviews from the US Food and Drug Administration as an example, drug approval packages are available on the agency’s website for drugs approved since 1997 (Turner 2013); for drugs approved before 1997, information must be requested through a freedom of information request. The drug approval packages contain various documents: approval letter(s), medical review(s), chemistry review(s), clinical pharmacology review(s), and statistical reviews(s).

Individual participant data (IPD) are usually sought directly from the researchers responsible for the study, or may be identified from open data repositories (e.g. www.clinicalstudydatarequest.com ). These data typically include variables that represent the characteristics of each participant, intervention (or exposure) group, prognostic factors, and measurements of outcomes (Stewart et al 2015). Access to IPD has the advantage of allowing review authors to reanalyse the data flexibly, in accordance with the preferred analysis methods outlined in the protocol, and can reduce the variation in analysis methods across studies included in the review. IPD reviews are addressed in detail in Chapter 26 .

MECIR Box 5.2.a Relevant expectations for conduct of intervention reviews

Examining errata ( )

Some studies may have been found to be fraudulent or may for other reasons have been retracted since publication. Errata can reveal important limitations, or even fatal flaws, in included studies. All of these may potentially lead to the exclusion of a study from a review or meta-analysis. Care should be taken to ensure that this information is retrieved in all database searches by downloading the appropriate fields together with the citation data.

5.2.1 Studies (not reports) as the unit of interest

In a systematic review, studies rather than reports of studies are the principal unit of interest. Since a study may have been reported in several sources, a comprehensive search for studies for the review may identify many reports from a potentially relevant study (Mayo-Wilson et al 2017a, Mayo-Wilson et al 2018). Conversely, a report may describe more than one study.

Multiple reports of the same study should be linked together (see MECIR Box 5.2.b ). Some authors prefer to link reports before they collect data, and collect data from across the reports onto a single form. Other authors prefer to collect data from each report and then link together the collected data across reports. Either strategy may be appropriate, depending on the nature of the reports at hand. It may not be clear that two reports relate to the same study until data collection has commenced. Although sometimes there is a single report for each study, it should never be assumed that this is the case.

MECIR Box 5.2.b Relevant expectations for conduct of intervention reviews

Collating multiple reports ( )

It is wrong to consider multiple reports of the same study as if they are multiple studies. Secondary reports of a study should not be discarded, however, since they may contain valuable information about the design and conduct. Review authors must choose and justify which report to use as a source for study results.

It can be difficult to link multiple reports from the same study, and review authors may need to do some ‘detective work’. Multiple sources about the same trial may not reference each other, do not share common authors (Gøtzsche 1989, Tramèr et al 1997), or report discrepant information about the study design, characteristics, outcomes, and results (von Elm et al 2004, Mayo-Wilson et al 2017a).

Some of the most useful criteria for linking reports are:

  • trial registration numbers;
  • authors’ names;
  • sponsor for the study and sponsor identifiers (e.g. grant or contract numbers);
  • location and setting (particularly if institutions, such as hospitals, are named);
  • specific details of the interventions (e.g. dose, frequency);
  • numbers of participants and baseline data; and
  • date and duration of the study (which also can clarify whether different sample sizes are due to different periods of recruitment), length of follow-up, or subgroups selected to address secondary goals.

Review authors should use as many trial characteristics as possible to link multiple reports. When uncertainties remain after considering these and other factors, it may be necessary to correspond with the study authors or sponsors for confirmation.

5.2.2 Determining which sources might be most useful

A comprehensive search to identify all eligible studies from all possible sources is resource-intensive but necessary for a high-quality systematic review (see Chapter 4 ). Because some data sources are more useful than others (Mayo-Wilson et al 2018), review authors should consider which data sources may be available and which may contain the most useful information for the review. These considerations should be described in the protocol. Table 5.2.a summarizes the strengths and limitations of different data sources (Mayo-Wilson et al 2018). Gaining access to CSRs and IPD often takes a long time. Review authors should begin searching repositories and contact trial investigators and sponsors as early as possible to negotiate data usage agreements (Mayo-Wilson et al 2015, Mayo-Wilson et al 2018).

Table 5.2.a Strengths and limitations of different data sources for systematic reviews

 

Found easily

Data extracted quickly

Include useful information about methods and results

Available for some, but not all studies (with a risk of reporting biases: see and )

Contain limited study characteristics and methods

Can omit outcomes, especially harms

Identify unpublished studies

Include little information about study design

Include limited and unclear information for meta-analysis

May result in double-counting studies in meta-analysis if not correctly linked to other reports of the same study

Identify otherwise unpublished trials

May contain information about design, risk of bias, and results not included in other public sources

Link multiple sources about the same trial using unique registration number

Limited to more recent studies that comply with registration requirements

Often contain limited information about trial design and quantitative results

May report only harms (adverse events) occurring above a threshold (e.g. 5%)

May be inaccurate or incomplete for trials whose methods have changed during the conduct of the study, or results not kept up to date

Identify studies not reported in other public sources

Describe details of methods and results not found in other sources

Available only for studies submitted to regulators

Available for approved indications, but not ‘off-label’ uses

Not always in a standard format

Not often available for old products

Contain detailed information about study characteristics, methods, and results

Can be particularly useful for identifying detailed information about harms

Describe aggregate results, which are easy to analyse and sufficient for most reviews

Do not exist or difficult to obtain for most studies

Require more time to obtain and analyse than public sources

Allow review authors to use contemporary statistical methods and to standardize analyses across studies

Permit additional analyses that the review authors desire (e.g. subgroup analyses)

Require considerable expertise and time to obtain and analyse

May lead to the same results that can be found in aggregate report

May not be necessary if one has a CSR

5.2.3 Correspondence with investigators

Review authors often find that they are unable to obtain all the information they seek from available reports about the details of the study design, the full range of outcomes measured and the numerical results. In such circumstances, authors are strongly encouraged to contact the original investigators (see MECIR Box 5.2.c ). Contact details of study authors, when not available from the study reports, often can be obtained from more recent publications, from university or institutional staff listings, from membership directories of professional societies, or by a general search of the web. If the contact author named in the study report cannot be contacted or does not respond, it is worthwhile attempting to contact other authors.

Review authors should consider the nature of the information they require and make their request accordingly. For descriptive information about the conduct of the trial, it may be most appropriate to ask open-ended questions (e.g. how was the allocation process conducted, or how were missing data handled?). If specific numerical data are required, it may be more helpful to request them specifically, possibly providing a short data collection form (either uncompleted or partially completed). If IPD are required, they should be specifically requested (see also Chapter 26 ). In some cases, study investigators may find it more convenient to provide IPD rather than conduct additional analyses to obtain the specific statistics requested.

MECIR Box 5.2.c Relevant expectations for conduct of intervention reviews

Obtaining unpublished data ( )

Contacting study authors to obtain or confirm data makes the review more complete, potentially enhances precision and reduces the impact of reporting biases. Missing information includes details to inform risk of bias assessments, details of interventions and outcomes, and study results (including breakdowns of results by important subgroups).

5.3 What data to collect

5.3.1 what are data.

For the purposes of this chapter, we define ‘data’ to be any information about (or derived from) a study, including details of methods, participants, setting, context, interventions, outcomes, results, publications, and investigators. Review authors should plan in advance what data will be required for their systematic review, and develop a strategy for obtaining them (see MECIR Box 5.3.a ). The involvement of consumers and other stakeholders can be helpful in ensuring that the categories of data collected are sufficiently aligned with the needs of review users ( Chapter 1, Section 1.3 ). The data to be sought should be described in the protocol, with consideration wherever possible of the issues raised in the rest of this chapter.

The data collected for a review should adequately describe the included studies, support the construction of tables and figures, facilitate the risk of bias assessment, and enable syntheses and meta-analyses. Review authors should familiarize themselves with reporting guidelines for systematic reviews (see online Chapter III and the PRISMA statement; (Liberati et al 2009) to ensure that relevant elements and sections are incorporated. The following sections review the types of information that should be sought, and these are summarized in Table 5.3.a (Li et al 2015).

MECIR Box 5.3.a Relevant expectations for conduct of intervention reviews

Describing studies ( )

Basic characteristics of each study will need to be presented as part of the review, including details of participants, interventions and comparators, outcomes and study design.

Table 5.3.a Checklist of items to consider in data collection

Name of data extractors, date of data extraction, and identification features of each report from which data are being extracted

Confirm eligibility of the study for the review

Reason for exclusion

Study design:

Recruitment and sampling procedures used (including at the level of individual participants and clusters/sites if relevant)

Enrolment start and end dates; length of participant follow-up

Details of random sequence generation, allocation sequence concealment, and masking for randomized trials, and methods used to prevent and control for confounding, selection biases, and information biases for non-randomized studies*

Methods used to prevent and address missing data*

Statistical analysis:

Unit of analysis (e.g. individual participant, clinic, village, body part)

Statistical methods used if computed effect estimates are extracted from reports, including any covariates included in the statistical model

Likelihood of reporting and other biases*

Source(s) of funding or other material support for the study

Authors’ financial relationship and other potential conflicts of interest

Setting

Region(s) and country/countries from which study participants were recruited

Study eligibility criteria, including diagnostic criteria

Characteristics of participants at the beginning (or baseline) of the study (e.g. age, sex, comorbidity, socio-economic status)

Description of the intervention(s) and comparison intervention(s), ideally with sufficient detail for replication:

For each pre-specified outcome domain (e.g. anxiety) in the systematic review:

)

For each group, and for each outcome at each time point: number of participants randomly assigned and included in the analysis; and number of participants who withdrew, were lost to follow-up or were excluded (with reasons for each)

Summary data for each group (e.g. 2×2 table for dichotomous data; means and standard deviations for continuous data)

Between-group estimates that quantify the effect of the intervention on the outcome, and their precision (e.g. risk ratio, odds ratio, mean difference)

If subgroup analysis is planned, the same information would need to be extracted for each participant subgroup

Key conclusions of the study authors

Reference to other relevant studies

Correspondence required

Miscellaneous comments from the study authors or by the review authors

*Full description required for assessments of risk of bias (see Chapter 8 , Chapter 23 and Chapter 25 ).

5.3.2 Study methods and potential sources of bias

Different research methods can influence study outcomes by introducing different biases into results. Important study design characteristics should be collected to allow the selection of appropriate methods for assessment and analysis, and to enable description of the design of each included study in a table of ‘Characteristics of included studies’, including whether the study is randomized, whether the study has a cluster or crossover design, and the duration of the study. If the review includes non-randomized studies, appropriate features of the studies should be described (see Chapter 24 ).

Detailed information should be collected to facilitate assessment of the risk of bias in each included study. Risk-of-bias assessment should be conducted using the tool most appropriate for the design of each study, and the information required to complete the assessment will depend on the tool. Randomized studies should be assessed using the tool described in Chapter 8 . The tool covers bias arising from the randomization process, due to deviations from intended interventions, due to missing outcome data, in measurement of the outcome, and in selection of the reported result. For each item in the tool, a description of what happened in the study is required, which may include verbatim quotes from study reports. Information for assessment of bias due to missing outcome data and selection of the reported result may be most conveniently collected alongside information on outcomes and results. Chapter 7 (Section 7.3.1) discusses some issues in the collection of information for assessments of risk of bias. For non-randomized studies, the most appropriate tool is described in Chapter 25 . A separate tool also covers bias due to missing results in meta-analysis (see Chapter 13 ).

A particularly important piece of information is the funding source of the study and potential conflicts of interest of the study authors.

Some review authors will wish to collect additional information on study characteristics that bear on the quality of the study’s conduct but that may not lead directly to risk of bias, such as whether ethical approval was obtained and whether a sample size calculation was performed a priori.

5.3.3 Participants and setting

Details of participants are collected to enable an understanding of the comparability of, and differences between, the participants within and between included studies, and to allow assessment of how directly or completely the participants in the included studies reflect the original review question.

Typically, aspects that should be collected are those that could (or are believed to) affect presence or magnitude of an intervention effect and those that could help review users assess applicability to populations beyond the review. For example, if the review authors suspect important differences in intervention effect between different socio-economic groups, this information should be collected. If intervention effects are thought constant over such groups, and if such information would not be useful to help apply results, it should not be collected. Participant characteristics that are often useful for assessing applicability include age and sex. Summary information about these should always be collected unless they are not obvious from the context. These characteristics are likely to be presented in different formats (e.g. ages as means or medians, with standard deviations or ranges; sex as percentages or counts for the whole study or for each intervention group separately). Review authors should seek consistent quantities where possible, and decide whether it is more relevant to summarize characteristics for the study as a whole or by intervention group. It may not be possible to select the most consistent statistics until data collection is complete across all or most included studies. Other characteristics that are sometimes important include ethnicity, socio-demographic details (e.g. education level) and the presence of comorbid conditions. Clinical characteristics relevant to the review question (e.g. glucose level for reviews on diabetes) also are important for understanding the severity or stage of the disease.

Diagnostic criteria that were used to define the condition of interest can be a particularly important source of diversity across studies and should be collected. For example, in a review of drug therapy for congestive heart failure, it is important to know how the definition and severity of heart failure was determined in each study (e.g. systolic or diastolic dysfunction, severe systolic dysfunction with ejection fractions below 20%). Similarly, in a review of antihypertensive therapy, it is important to describe baseline levels of blood pressure of participants.

If the settings of studies may influence intervention effects or applicability, then information on these should be collected. Typical settings of healthcare intervention studies include acute care hospitals, emergency facilities, general practice, and extended care facilities such as nursing homes, offices, schools, and communities. Sometimes studies are conducted in different geographical regions with important differences that could affect delivery of an intervention and its outcomes, such as cultural characteristics, economic context, or rural versus city settings. Timing of the study may be associated with important technology differences or trends over time. If such information is important for the interpretation of the review, it should be collected.

Important characteristics of the participants in each included study should be summarized for the reader in the table of ‘Characteristics of included studies’.

5.3.4 Interventions

Details of all experimental and comparator interventions of relevance to the review should be collected. Again, details are required for aspects that could affect the presence or magnitude of an effect or that could help review users assess applicability to their own circumstances. Where feasible, information should be sought (and presented in the review) that is sufficient for replication of the interventions under study. This includes any co-interventions administered as part of the study, and applies similarly to comparators such as ‘usual care’. Review authors may need to request missing information from study authors.

The Template for Intervention Description and Replication (TIDieR) provides a comprehensive framework for full description of interventions and has been proposed for use in systematic reviews as well as reports of primary studies (Hoffmann et al 2014). The checklist includes descriptions of:

  • the rationale for the intervention and how it is expected to work;
  • any documentation that instructs the recipient on the intervention;
  • what the providers do to deliver the intervention (procedures and processes);
  • who provides the intervention (including their skill level), how (e.g. face to face, web-based) and in what setting (e.g. home, school, or hospital);
  • the timing and intensity;
  • whether any variation is permitted or expected, and whether modifications were actually made; and
  • any strategies used to ensure or assess fidelity or adherence to the intervention, and the extent to which the intervention was delivered as planned.

For clinical trials of pharmacological interventions, key information to collect will often include routes of delivery (e.g. oral or intravenous delivery), doses (e.g. amount or intensity of each treatment, frequency of delivery), timing (e.g. within 24 hours of diagnosis), and length of treatment. For other interventions, such as those that evaluate psychotherapy, behavioural and educational approaches, or healthcare delivery strategies, the amount of information required to characterize the intervention will typically be greater, including information about multiple elements of the intervention, who delivered it, and the format and timing of delivery. Chapter 17 provides further information on how to manage intervention complexity, and how the intervention Complexity Assessment Tool (iCAT) can facilitate data collection (Lewin et al 2017).

Important characteristics of the interventions in each included study should be summarized for the reader in the table of ‘Characteristics of included studies’. Additional tables or diagrams such as logic models ( Chapter 2, Section 2.5.1 ) can assist descriptions of multi-component interventions so that review users can better assess review applicability to their context.

5.3.4.1 Integrity of interventions

The degree to which specified procedures or components of the intervention are implemented as planned can have important consequences for the findings from a study. We describe this as intervention integrity ; related terms include adherence, compliance and fidelity (Carroll et al 2007). The verification of intervention integrity may be particularly important in reviews of non-pharmacological trials such as behavioural interventions and complex interventions, which are often implemented in conditions that present numerous obstacles to idealized delivery.

It is generally expected that reports of randomized trials provide detailed accounts of intervention implementation (Zwarenstein et al 2008, Moher et al 2010). In assessing whether interventions were implemented as planned, review authors should bear in mind that some interventions are standardized (with no deviations permitted in the intervention protocol), whereas others explicitly allow a degree of tailoring (Zwarenstein et al 2008). In addition, the growing field of implementation science has led to an increased awareness of the impact of setting and context on delivery of interventions (Damschroder et al 2009). (See Chapter 17, Section 17.1.2.1 for further information and discussion about how an intervention may be tailored to local conditions in order to preserve its integrity.)

Information about integrity can help determine whether unpromising results are due to a poorly conceptualized intervention or to an incomplete delivery of the prescribed components. It can also reveal important information about the feasibility of implementing a given intervention in real life settings. If it is difficult to achieve full implementation in practice, the intervention will have low feasibility (Dusenbury et al 2003).

Whether a lack of intervention integrity leads to a risk of bias in the estimate of its effect depends on whether review authors and users are interested in the effect of assignment to intervention or the effect of adhering to intervention, as discussed in more detail in Chapter 8, Section 8.2.2 . Assessment of deviations from intended interventions is important for assessing risk of bias in the latter, but not the former (see Chapter 8, Section 8.4 ), but both may be of interest to decision makers in different ways.

An example of a Cochrane Review evaluating intervention integrity is provided by a review of smoking cessation in pregnancy (Chamberlain et al 2017). The authors found that process evaluation of the intervention occurred in only some trials and that the implementation was less than ideal in others, including some of the largest trials. The review highlighted how the transfer of an intervention from one setting to another may reduce its effectiveness when elements are changed, or aspects of the materials are culturally inappropriate.

5.3.4.2 Process evaluations

Process evaluations seek to evaluate the process (and mechanisms) between the intervention’s intended implementation and the actual effect on the outcome (Moore et al 2015). Process evaluation studies are characterized by a flexible approach to data collection and the use of numerous methods to generate a range of different types of data, encompassing both quantitative and qualitative methods. Guidance for including process evaluations in systematic reviews is provided in Chapter 21 . When it is considered important, review authors should aim to collect information on whether the trial accounted for, or measured, key process factors and whether the trials that thoroughly addressed integrity showed a greater impact. Process evaluations can be a useful source of factors that potentially influence the effectiveness of an intervention.

5.3.5 Outcome s

An outcome is an event or a measurement value observed or recorded for a particular person or intervention unit in a study during or following an intervention, and that is used to assess the efficacy and safety of the studied intervention (Meinert 2012). Review authors should indicate in advance whether they plan to collect information about all outcomes measured in a study or only those outcomes of (pre-specified) interest in the review. Research has shown that trials addressing the same condition and intervention seldom agree on which outcomes are the most important, and consequently report on numerous different outcomes (Dwan et al 2014, Ismail et al 2014, Denniston et al 2015, Saldanha et al 2017a). The selection of outcomes across systematic reviews of the same condition is also inconsistent (Page et al 2014, Saldanha et al 2014, Saldanha et al 2016, Liu et al 2017). Outcomes used in trials and in systematic reviews of the same condition have limited overlap (Saldanha et al 2017a, Saldanha et al 2017b).

We recommend that only the outcomes defined in the protocol be described in detail. However, a complete list of the names of all outcomes measured may allow a more detailed assessment of the risk of bias due to missing outcome data (see Chapter 13 ).

Review authors should collect all five elements of an outcome (Zarin et al 2011, Saldanha et al 2014):

1. outcome domain or title (e.g. anxiety);

2. measurement tool or instrument (including definition of clinical outcomes or endpoints); for a scale, name of the scale (e.g. the Hamilton Anxiety Rating Scale), upper and lower limits, and whether a high or low score is favourable, definitions of any thresholds if appropriate;

3. specific metric used to characterize each participant’s results (e.g. post-intervention anxiety, or change in anxiety from baseline to a post-intervention time point, or post-intervention presence of anxiety (yes/no));

4. method of aggregation (e.g. mean and standard deviation of anxiety scores in each group, or proportion of people with anxiety);

5. timing of outcome measurements (e.g. assessments at end of eight-week intervention period, events occurring during eight-week intervention period).

Further considerations for economics outcomes are discussed in Chapter 20 , and for patient-reported outcomes in Chapter 18 .

5.3.5.1 Adverse effects

Collection of information about the harmful effects of an intervention can pose particular difficulties, discussed in detail in Chapter 19 . These outcomes may be described using multiple terms, including ‘adverse event’, ‘adverse effect’, ‘adverse drug reaction’, ‘side effect’ and ‘complication’. Many of these terminologies are used interchangeably in the literature, although some are technically different. Harms might additionally be interpreted to include undesirable changes in other outcomes measured during a study, such as a decrease in quality of life where an improvement may have been anticipated.

In clinical trials, adverse events can be collected either systematically or non-systematically. Systematic collection refers to collecting adverse events in the same manner for each participant using defined methods such as a questionnaire or a laboratory test. For systematically collected outcomes representing harm, data can be collected by review authors in the same way as efficacy outcomes (see Section 5.3.5 ).

Non-systematic collection refers to collection of information on adverse events using methods such as open-ended questions (e.g. ‘Have you noticed any symptoms since your last visit?’), or reported by participants spontaneously. In either case, adverse events may be selectively reported based on their severity, and whether the participant suspected that the effect may have been caused by the intervention, which could lead to bias in the available data. Unfortunately, most adverse events are collected non-systematically rather than systematically, creating a challenge for review authors. The following pieces of information are useful and worth collecting (Nicole Fusco, personal communication):

  • any coding system or standard medical terminology used (e.g. COSTART, MedDRA), including version number;
  • name of the adverse events (e.g. dizziness);
  • reported intensity of the adverse event (e.g. mild, moderate, severe);
  • whether the trial investigators categorized the adverse event as ‘serious’;
  • whether the trial investigators identified the adverse event as being related to the intervention;
  • time point (most commonly measured as a count over the duration of the study);
  • any reported methods for how adverse events were selected for inclusion in the publication (e.g. ‘We reported all adverse events that occurred in at least 5% of participants’); and
  • associated results.

Different collection methods lead to very different accounting of adverse events (Safer 2002, Bent et al 2006, Ioannidis et al 2006, Carvajal et al 2011, Allen et al 2013). Non-systematic collection methods tend to underestimate how frequently an adverse event occurs. It is particularly problematic when the adverse event of interest to the review is collected systematically in some studies but non-systematically in other studies. Different collection methods introduce an important source of heterogeneity. In addition, when non-systematic adverse events are reported based on quantitative selection criteria (e.g. only adverse events that occurred in at least 5% of participants were included in the publication), use of reported data alone may bias the results of meta-analyses. Review authors should be cautious of (or refrain from) synthesizing adverse events that are collected differently.

Regardless of the collection methods, precise definitions of adverse effect outcomes and their intensity should be recorded, since they may vary between studies. For example, in a review of aspirin and gastrointestinal haemorrhage, some trials simply reported gastrointestinal bleeds, while others reported specific categories of bleeding, such as haematemesis, melaena, and proctorrhagia (Derry and Loke 2000). The definition and reporting of severity of the haemorrhages (e.g. major, severe, requiring hospital admission) also varied considerably among the trials (Zanchetti and Hansson 1999). Moreover, a particular adverse effect may be described or measured in different ways among the studies. For example, the terms ‘tiredness’, ‘fatigue’ or ‘lethargy’ may all be used in reporting of adverse effects. Study authors also may use different thresholds for ‘abnormal’ results (e.g. hypokalaemia diagnosed at a serum potassium concentration of 3.0 mmol/L or 3.5 mmol/L).

No mention of adverse events in trial reports does not necessarily mean that no adverse events occurred. It is usually safest to assume that they were not reported. Quality of life measures are sometimes used as a measure of the participants’ experience during the study, but these are usually general measures that do not look specifically at particular adverse effects of the intervention. While quality of life measures are important and can be used to gauge overall participant well-being, they should not be regarded as substitutes for a detailed evaluation of safety and tolerability.

5.3.6 Results

Results data arise from the measurement or ascertainment of outcomes for individual participants in an intervention study. Results data may be available for each individual in a study (i.e. individual participant data; see Chapter 26 ), or summarized at arm level, or summarized at study level into an intervention effect by comparing two intervention arms. Results data should be collected only for the intervention groups and outcomes specified to be of interest in the protocol (see MECIR Box 5.3.b ). Results for other outcomes should not be collected unless the protocol is modified to add them. Any modification should be reported in the review. However, review authors should be alert to the possibility of important, unexpected findings, particularly serious adverse effects.

MECIR Box 5.3.b Relevant expectations for conduct of intervention reviews

Choosing intervention groups in multi-arm studies ( )

There is no point including irrelevant interventions in the review. Authors should, however, make it clear in the table of ‘Characteristics of included studies’ that these interventions were present in the study.

Reports of studies often include several results for the same outcome. For example, different measurement scales might be used, results may be presented separately for different subgroups, and outcomes may have been measured at different follow-up time points. Variation in the results can be very large, depending on which data are selected (Gøtzsche et al 2007, Mayo-Wilson et al 2017a). Review protocols should be as specific as possible about which outcome domains, measurement tools, time points, and summary statistics (e.g. final values versus change from baseline) are to be collected (Mayo-Wilson et al 2017b). A framework should be pre-specified in the protocol to facilitate making choices between multiple eligible measures or results. For example, a hierarchy of preferred measures might be created, or plans articulated to select the result with the median effect size, or to average across all eligible results for a particular outcome domain (see also Chapter 9, Section 9.3.3 ). Any additional decisions or changes to this framework made once the data are collected should be reported in the review as changes to the protocol.

Section 5.6 describes the numbers that will be required to perform meta-analysis, if appropriate. The unit of analysis (e.g. participant, cluster, body part, treatment period) should be recorded for each result when it is not obvious (see Chapter 6, Section 6.2 ). The type of outcome data determines the nature of the numbers that will be sought for each outcome. For example, for a dichotomous (‘yes’ or ‘no’) outcome, the number of participants and the number who experienced the outcome will be sought for each group. It is important to collect the sample size relevant to each result, although this is not always obvious. A flow diagram as recommended in the CONSORT Statement (Moher et al 2001) can help to determine the flow of participants through a study. If one is not available in a published report, review authors can consider drawing one (available from www.consort-statement.org ).

The numbers required for meta-analysis are not always available. Often, other statistics can be collected and converted into the required format. For example, for a continuous outcome, it is usually most convenient to seek the number of participants, the mean and the standard deviation for each intervention group. These are often not available directly, especially the standard deviation. Alternative statistics enable calculation or estimation of the missing standard deviation (such as a standard error, a confidence interval, a test statistic (e.g. from a t-test or F-test) or a P value). These should be extracted if they provide potentially useful information (see MECIR Box 5.3.c ). Details of recalculation are provided in Section 5.6 . Further considerations for dealing with missing data are discussed in Chapter 10, Section 10.12 .

MECIR Box 5.3.c Relevant expectations for conduct of intervention reviews

Making maximal use of data ( )

) or P values, or even data for individual participants Data entry into RevMan is easiest when 2×2 tables are reported for dichotomous outcomes, and when means and standard deviations are presented for continuous outcomes. Sometimes these statistics are not reported but some manipulations of the reported data can be performed to obtain them. For instance, 2×2 tables can often be derived from sample sizes and percentages, while standard deviations can often be computed using confidence intervals or P values. Furthermore, the inverse-variance data entry format can be used even if the detailed data required for dichotomous or continuous data are not available, for instance if only odds ratios and their confidence intervals are presented. The RevMan calculator facilitates many of these manipulations.

Checking accuracy of numeric data in the review ( )

This is a reasonably straightforward way for authors to check a number of potential problems, including typographical errors in studies’ reports, accuracy of data collection and manipulation, and data entry into RevMan.  For example, the direction of a standardized mean difference may accidentally be wrong in the review. A basic check is to ensure the same qualitative findings (e.g. direction of effect and statistical significance) between the data as presented in the review and the data as available from the original study. Results in forest plots should agree with data in the original report (point estimate and confidence interval) if the same effect measure and statistical model is used.

5.3.7 Other information to collect

We recommend that review authors collect the key conclusions of the included study as reported by its authors. It is not necessary to report these conclusions in the review, but they should be used to verify the results of analyses undertaken by the review authors, particularly in relation to the direction of effect. Further comments by the study authors, for example any explanations they provide for unexpected findings, may be noted. References to other studies that are cited in the study report may be useful, although review authors should be aware of the possibility of citation bias (see Chapter 7, Section 7.2.3.2 ). Documentation of any correspondence with the study authors is important for review transparency.

5.4 Data collection tools

5.4.1 rationale for data collection forms.

Data collection for systematic reviews should be performed using structured data collection forms (see MECIR Box 5.4.a ). These can be paper forms, electronic forms (e.g. Google Form), or commercially or custom-built data systems (e.g. Covidence, EPPI-Reviewer, Systematic Review Data Repository (SRDR)) that allow online form building, data entry by several users, data sharing, and efficient data management (Li et al 2015). All different means of data collection require data collection forms.

MECIR Box 5.4.a Relevant expectations for conduct of intervention reviews

Using data collection forms ( )

Review authors often have different backgrounds and level of systematic review experience. Using a data collection form ensures some consistency in the process of data extraction, and is necessary for comparing data extracted in duplicate. The completed data collection forms should be available to the CRG on request. Piloting the form within the review team is highly desirable. At minimum, the data collection form (or a very close variant of it) must have been assessed for usability.

The data collection form is a bridge between what is reported by the original investigators (e.g. in journal articles, abstracts, personal correspondence) and what is ultimately reported by the review authors. The data collection form serves several important functions (Meade and Richardson 1997). First, the form is linked directly to the review question and criteria for assessing eligibility of studies, and provides a clear summary of these that can be used to identify and structure the data to be extracted from study reports. Second, the data collection form is the historical record of the provenance of the data used in the review, as well as the multitude of decisions (and changes to decisions) that occur throughout the review process. Third, the form is the source of data for inclusion in an analysis.

Given the important functions of data collection forms, ample time and thought should be invested in their design. Because each review is different, data collection forms will vary across reviews. However, there are many similarities in the types of information that are important. Thus, forms can be adapted from one review to the next. Although we use the term ‘data collection form’ in the singular, in practice it may be a series of forms used for different purposes: for example, a separate form could be used to assess the eligibility of studies for inclusion in the review to assist in the quick identification of studies to be excluded from or included in the review.

5.4.2 Considerations in selecting data collection tools

The choice of data collection tool is largely dependent on review authors’ preferences, the size of the review, and resources available to the author team. Potential advantages and considerations of selecting one data collection tool over another are outlined in Table 5.4.a (Li et al 2015). A significant advantage that data systems have is in data management ( Chapter 1, Section 1.6 ) and re-use. They make review updates more efficient, and also facilitate methodological research across reviews. Numerous ‘meta-epidemiological’ studies have been carried out using Cochrane Review data, resulting in methodological advances which would not have been possible if thousands of studies had not all been described using the same data structures in the same system.

Some data collection tools facilitate automatic imports of extracted data into RevMan (Cochrane’s authoring tool), such as CSV (Excel) and Covidence. Details available here https://documentation.cochrane.org/revman-kb/populate-study-data-260702462.html

Table 5.4.a Considerations in selecting data collection tools

Examples

Forms developed using word processing software

Microsoft Access

Google Forms

Covidence

EPPI-Reviewer

Systematic Review Data Repository (SRDR)

DistillerSR (Evidence Partners)

Doctor Evidence

Suitable review type and team sizes

Small-scale reviews (<10 included studies)

Small team with 2 to 3 data extractors in the same physical location

Small- to medium-scale reviews (10 to 20 studies)

Small to moderate-sized team with 4 to 6 data extractors

For small-, medium-, and especially large-scale reviews (>20 studies), as well as reviews that need constant updating

All team sizes, especially large teams (i.e. >6 data extractors)

Resource needs

Low

Low to medium

Low (open-access tools such as Covidence or SRDR, or tools for which authors have institutional licences)

High (commercial data systems with no access via an institutional licence)

Advantages

Do not rely on access to computer and network or internet connectivity

Can record notes and explanations easily

Require minimal software skills

Allow extracted data to be processed electronically for editing and analysis

Allow electronic data storage, sharing and collation

Easy to expand or edit forms as required

Can automate data comparison with additional programming

Can copy data to analysis software without manual re-entry, reducing errors

Specifically designed for data collection for systematic reviews

Allow online data storage, linking, and sharing

Easy to expand or edit forms as required

Can be integrated with title/abstract, full-text screening and other functions

Can link data items to locations in the report to facilitate checking

Can readily automate data comparison between independent data collection for the same study

Allow easy monitoring of progress and performance of the author team

Facilitate coordination among data collectors such as allocation of studies for collection and monitoring team progress

Allow simultaneous data entry by multiple authors

Can export data directly to analysis software

In some cases, improve public accessibility through open data sharing

Disadvantages

Inefficient and potentially unreliable because data must be entered into software for analysis and reporting

Susceptible to errors

Data collected by multiple authors must be manually collated

Difficult to amend as the review progresses

If the papers are lost, all data will need to be re-created

Require familiarity with software packages to design and use forms

Susceptible to changes in software versions

Upfront investment of resources to set up the form and train data extractors

Structured templates may not be as flexible as electronic forms

Cost of commercial data systems

Require familiarity with data systems

Susceptible to changes in software versions

5.4.3 Design of a data collection form

Regardless of whether data are collected using a paper or electronic form, or a data system, the key to successful data collection is to construct easy-to-use forms and collect sufficient and unambiguous data that faithfully represent the source in a structured and organized manner (Li et al 2015). In most cases, a document format should be developed for the form before building an electronic form or a data system. This can be distributed to others, including programmers and data analysts, and as a guide for creating an electronic form and any guidance or codebook to be used by data extractors. Review authors also should consider compatibility of any electronic form or data system with analytical software, as well as mechanisms for recording, assessing and correcting data entry errors.

Data described in multiple reports (or even within a single report) of a study may not be consistent. Review authors will need to describe how they work with multiple reports in the protocol, for example, by pre-specifying which report will be used when sources contain conflicting data that cannot be resolved by contacting the investigators. Likewise, when there is only one report identified for a study, review authors should specify the section within the report (e.g. abstract, methods, results, tables, and figures) for use in case of inconsistent information.

If review authors wish to automatically import their extracted data into RevMan, it is advised that their data collection forms match the data extraction templates available via the RevMan Knowledge Base. Details available here https://documentation.cochrane.org/revman-kb/data-extraction-templates-260702375.html.

A good data collection form should minimize the need to go back to the source documents. When designing a data collection form, review authors should involve all members of the team, that is, content area experts, authors with experience in systematic review methods and data collection form design, statisticians, and persons who will perform data extraction. Here are suggested steps and some tips for designing a data collection form, based on the informal collation of experiences from numerous review authors (Li et al 2015).

Step 1. Develop outlines of tables and figures expected to appear in the systematic review, considering the comparisons to be made between different interventions within the review, and the various outcomes to be measured. This step will help review authors decide the right amount of data to collect (not too much or too little). Collecting too much information can lead to forms that are longer than original study reports, and can be very wasteful of time. Collection of too little information, or omission of key data, can lead to the need to return to study reports later in the review process.

Step 2. Assemble and group data elements to facilitate form development. Review authors should consult Table 5.3.a , in which the data elements are grouped to facilitate form development and data collection. Note that it may be more efficient to group data elements in the order in which they are usually found in study reports (e.g. starting with reference information, followed by eligibility criteria, intervention description, statistical methods, baseline characteristics and results).

Step 3. Identify the optimal way of framing the data items. Much has been written about how to frame data items for developing robust data collection forms in primary research studies. We summarize a few key points and highlight issues that are pertinent to systematic reviews.

  • Ask closed-ended questions (i.e. questions that define a list of permissible responses) as much as possible. Closed-ended questions do not require post hoc coding and provide better control over data quality than open-ended questions. When setting up a closed-ended question, one must anticipate and structure possible responses and include an ‘other, specify’ category because the anticipated list may not be exhaustive. Avoid asking data extractors to summarize data into uncoded text, no matter how short it is.
  • Avoid asking a question in a way that the response may be left blank. Include ‘not applicable’, ‘not reported’ and ‘cannot tell’ options as needed. The ‘cannot tell’ option tags uncertain items that may promote review authors to contact study authors for clarification, especially on data items critical to reach conclusions.
  • Remember that the form will focus on what is reported in the article rather what has been done in the study. The study report may not fully reflect how the study was actually conducted. For example, a question ‘Did the article report that the participants were masked to the intervention?’ is more appropriate than ‘Were participants masked to the intervention?’
  • Where a judgement is required, record the raw data (i.e. quote directly from the source document) used to make the judgement. It is also important to record the source of information collected, including where it was found in a report or whether information was obtained from unpublished sources or personal communications. As much as possible, questions should be asked in a way that minimizes subjective interpretation and judgement to facilitate data comparison and adjudication.
  • Incorporate flexibility to allow for variation in how data are reported. It is strongly recommended that outcome data be collected in the format in which they were reported and transformed in a subsequent step if required. Review authors also should consider the software they will use for analysis and for publishing the review (e.g. RevMan).

Step 4. Develop and pilot-test data collection forms, ensuring that they provide data in the right format and structure for subsequent analysis. In addition to data items described in Step 2, data collection forms should record the title of the review as well as the person who is completing the form and the date of completion. Forms occasionally need revision; forms should therefore include the version number and version date to reduce the chances of using an outdated form by mistake. Because a study may be associated with multiple reports, it is important to record the study ID as well as the report ID. Definitions and instructions helpful for answering a question should appear next to the question to improve quality and consistency across data extractors (Stock 1994). Provide space for notes, regardless of whether paper or electronic forms are used.

All data collection forms and data systems should be thoroughly pilot-tested before launch (see MECIR Box 5.4.a ). Testing should involve several people extracting data from at least a few articles. The initial testing focuses on the clarity and completeness of questions. Users of the form may provide feedback that certain coding instructions are confusing or incomplete (e.g. a list of options may not cover all situations). The testing may identify data that are missing from the form, or likely to be superfluous. After initial testing, accuracy of the extracted data should be checked against the source document or verified data to identify problematic areas. It is wise to draft entries for the table of ‘Characteristics of included studies’ and complete a risk of bias assessment ( Chapter 8 ) using these pilot reports to ensure all necessary information is collected. A consensus between review authors may be required before the form is modified to avoid any misunderstandings or later disagreements. It may be necessary to repeat the pilot testing on a new set of reports if major changes are needed after the first pilot test.

Problems with the data collection form may surface after pilot testing has been completed, and the form may need to be revised after data extraction has started. When changes are made to the form or coding instructions, it may be necessary to return to reports that have already undergone data extraction. In some situations, it may be necessary to clarify only coding instructions without modifying the actual data collection form.

5.5 Extracting data from reports

5.5.1 introduction.

In most systematic reviews, the primary source of information about each study is published reports of studies, usually in the form of journal articles. Despite recent developments in machine learning models to automate data extraction in systematic reviews (see Section 5.5.9 ), data extraction is still largely a manual process. Electronic searches for text can provide a useful aid to locating information within a report. Examples include using search facilities in PDF viewers, internet browsers and word processing software. However, text searching should not be considered a replacement for reading the report, since information may be presented using variable terminology and presented in multiple formats.

5.5.2 Who should extract data?

Data extractors should have at least a basic understanding of the topic, and have knowledge of study design, data analysis and statistics. They should pay attention to detail while following instructions on the forms. Because errors that occur at the data extraction stage are rarely detected by peer reviewers, editors, or users of systematic reviews, it is recommended that more than one person extract data from every report to minimize errors and reduce introduction of potential biases by review authors (see MECIR Box 5.5.a ). As a minimum, information that involves subjective interpretation and information that is critical to the interpretation of results (e.g. outcome data) should be extracted independently by at least two people (see MECIR Box 5.5.a ). In common with implementation of the selection process ( Chapter 4, Section 4.6 ), it is preferable that data extractors are from complementary disciplines, for example a methodologist and a topic area specialist. It is important that everyone involved in data extraction has practice using the form and, if the form was designed by someone else, receives appropriate training.

Evidence in support of duplicate data extraction comes from several indirect sources. One study observed that independent data extraction by two authors resulted in fewer errors than data extraction by a single author followed by verification by a second (Buscemi et al 2006). A high prevalence of data extraction errors (errors in 20 out of 34 reviews) has been observed (Jones et al 2005). A further study of data extraction to compute standardized mean differences found that a minimum of seven out of 27 reviews had substantial errors (Gøtzsche et al 2007).

MECIR Box 5.5.a Relevant expectations for conduct of intervention reviews

Extracting study characteristics in duplicate ( )

Duplicating the data extraction process reduces both the risk of making mistakes and the possibility that data selection is influenced by a single person’s biases. Dual data extraction may be less important for study characteristics than it is for outcome data, so it is not a mandatory standard for the former.

Extracting outcome data in duplicate ( )

Duplicating the data extraction process reduces both the risk of making mistakes and the possibility that data selection is influenced by a single person’s biases. Dual data extraction is particularly important for outcome data, which feed directly into syntheses of the evidence and hence to conclusions of the review.

5.5.3 Training data extractors

Training of data extractors is intended to familiarize them with the review topic and methods, the data collection form or data system, and issues that may arise during data extraction. Results of the pilot testing of the form should prompt discussion among review authors and extractors of ambiguous questions or responses to establish consistency. Training should take place at the onset of the data extraction process and periodically over the course of the project (Li et al 2015). For example, when data related to a single item on the form are present in multiple locations within a report (e.g. abstract, main body of text, tables, and figures) or in several sources (e.g. publications, ClinicalTrials.gov, or CSRs), the development and documentation of instructions to follow an agreed algorithm are critical and should be reinforced during the training sessions.

Some have proposed that some information in a report, such as its authors, be blinded to the review author prior to data extraction and assessment of risk of bias (Jadad et al 1996). However, blinding of review authors to aspects of study reports generally is not recommended for Cochrane Reviews as there is little evidence that it alters the decisions made (Berlin 1997).

5.5.4 Extracting data from multiple reports of the same study

Studies frequently are reported in more than one publication or in more than one source (Tramèr et al 1997, von Elm et al 2004). A single source rarely provides complete information about a study; on the other hand, multiple sources may contain conflicting information about the same study (Mayo-Wilson et al 2017a, Mayo-Wilson et al 2017b, Mayo-Wilson et al 2018). Because the unit of interest in a systematic review is the study and not the report, information from multiple reports often needs to be collated and reconciled. It is not appropriate to discard any report of an included study without careful examination, since it may contain valuable information not included in the primary report. Review authors will need to decide between two strategies:

  • Extract data from each report separately, then combine information across multiple data collection forms.
  • Extract data from all reports directly into a single data collection form.

The choice of which strategy to use will depend on the nature of the reports and may vary across studies and across reports. For example, when a full journal article and multiple conference abstracts are available, it is likely that the majority of information will be obtained from the journal article; completing a new data collection form for each conference abstract may be a waste of time. Conversely, when there are two or more detailed journal articles, perhaps relating to different periods of follow-up, then it is likely to be easier to perform data extraction separately for these articles and collate information from the data collection forms afterwards. When data from all reports are extracted into a single data collection form, review authors should identify the ‘main’ data source for each study when sources include conflicting data and these differences cannot be resolved by contacting authors (Mayo-Wilson et al 2018). Flow diagrams such as those modified from the PRISMA statement can be particularly helpful when collating and documenting information from multiple reports (Mayo-Wilson et al 2018).

5.5.5 Reliability and reaching consensus

When more than one author extracts data from the same reports, there is potential for disagreement. After data have been extracted independently by two or more extractors, responses must be compared to assure agreement or to identify discrepancies. An explicit procedure or decision rule should be specified in the protocol for identifying and resolving disagreements. Most often, the source of the disagreement is an error by one of the extractors and is easily resolved. Thus, discussion among the authors is a sensible first step. More rarely, a disagreement may require arbitration by another person. Any disagreement that cannot be resolved should be addressed by contacting the study authors; if this is unsuccessful, the disagreement should be reported in the review.

The presence and resolution of disagreements should be carefully recorded. Maintaining a copy of the data ‘as extracted’ (in addition to the consensus data) allows assessment of reliability of coding. Examples of ways in which this can be achieved include the following:

  • Use one author’s (paper) data collection form and record changes after consensus in a different ink colour.
  • Enter consensus data onto an electronic form.
  • Record original data extracted and consensus data in separate forms (some online tools do this automatically).

Agreement of coded items before reaching consensus can be quantified, for example using kappa statistics (Orwin 1994), although this is not routinely done in Cochrane Reviews. If agreement is assessed, this should be done only for the most important data (e.g. key risk of bias assessments, or availability of key outcomes).

Throughout the review process informal consideration should be given to the reliability of data extraction. For example, if after reaching consensus on the first few studies, the authors note a frequent disagreement for specific data, then coding instructions may need modification. Furthermore, an author’s coding strategy may change over time, as the coding rules are forgotten, indicating a need for retraining and, possibly, some recoding.

5.5.6 Extracting data from clinical study reports

Clinical study reports (CSRs) obtained for a systematic review are likely to be in PDF format. Although CSRs can be thousands of pages in length and very time-consuming to review, they typically follow the content and format required by the International Conference on Harmonisation (ICH 1995). Information in CSRs is usually presented in a structured and logical way. For example, numerical data pertaining to important demographic, efficacy, and safety variables are placed within the main text in tables and figures. Because of the clarity and completeness of information provided in CSRs, data extraction from CSRs may be clearer and conducted more confidently than from journal articles or other short reports.

To extract data from CSRs efficiently, review authors should familiarize themselves with the structure of the CSRs. In practice, review authors may want to browse or create ‘bookmarks’ within a PDF document that record section headers and subheaders and search key words related to the data extraction (e.g. randomization). In addition, it may be useful to utilize optical character recognition software to convert tables of data in the PDF to an analysable format when additional analyses are required, saving time and minimizing transcription errors.

CSRs may contain many outcomes and present many results for a single outcome (due to different analyses) (Mayo-Wilson et al 2017b). We recommend review authors extract results only for outcomes of interest to the review (Section 5.3.6 ). With regard to different methods of analysis, review authors should have a plan and pre-specify preferred metrics in their protocol for extracting results pertaining to different populations (e.g. ‘all randomized’, ‘all participants taking at least one dose of medication’), methods for handling missing data (e.g. ‘complete case analysis’, ‘multiple imputation’), and adjustment (e.g. unadjusted, adjusted for baseline covariates). It may be important to record the range of analysis options available, even if not all are extracted in detail. In some cases it may be preferable to use metrics that are comparable across multiple included studies, which may not be clear until data collection for all studies is complete.

CSRs are particularly useful for identifying outcomes assessed but not presented to the public. For efficacy outcomes and systematically collected adverse events, review authors can compare what is described in the CSRs with what is reported in published reports to assess the risk of bias due to missing outcome data ( Chapter 8, Section 8.5 ) and in selection of reported result ( Chapter 8, Section 8.7 ). Note that non-systematically collected adverse events are not amenable to such comparisons because these adverse events may not be known ahead of time and thus not pre-specified in the protocol.

5.5.7 Extracting data from regulatory reviews

Data most relevant to systematic reviews can be found in the medical and statistical review sections of a regulatory review. Both of these are substantially longer than journal articles (Turner 2013). A list of all trials on a drug usually can be found in the medical review. Because trials are referenced by a combination of numbers and letters, it may be difficult for the review authors to link the trial with other reports of the same trial (Section 5.2.1 ).

Many of the documents downloaded from the US Food and Drug Administration’s website for older drugs are scanned copies and are not searchable because of redaction of confidential information (Turner 2013). Optical character recognition software can convert most of the text. Reviews for newer drugs have been redacted electronically; documents remain searchable as a result.

Compared to CSRs, regulatory reviews contain less information about trial design, execution, and results. They provide limited information for assessing the risk of bias. In terms of extracting outcomes and results, review authors should follow the guidance provided for CSRs (Section 5.5.6 ).

5.5.8 Extracting data from figures with software

Sometimes numerical data needed for systematic reviews are only presented in figures. Review authors may request the data from the study investigators, or alternatively, extract the data from the figures either manually (e.g. with a ruler) or by using software. Numerous tools are available, many of which are free. Those available at the time of writing include tools called Plot Digitizer, WebPlotDigitizer, Engauge, Dexter, ycasd, GetData Graph Digitizer. The software works by taking an image of a figure and then digitizing the data points off the figure using the axes and scales set by the users. The numbers exported can be used for systematic reviews, although additional calculations may be needed to obtain the summary statistics, such as calculation of means and standard deviations from individual-level data points (or conversion of time-to-event data presented on Kaplan-Meier plots to hazard ratios; see Chapter 6, Section 6.8.2 ).

It has been demonstrated that software is more convenient and accurate than visual estimation or use of a ruler (Gross et al 2014, Jelicic Kadic et al 2016). Review authors should consider using software for extracting numerical data from figures when the data are not available elsewhere.

5.5.9 Automating data extraction in systematic reviews

Because data extraction is time-consuming and error-prone, automating or semi-automating this step may make the extraction process more efficient and accurate. The state of science relevant to automating data extraction is summarized here (Jonnalagadda et al 2015).

  • At least 26 studies have tested various natural language processing and machine learning approaches for facilitating data extraction for systematic reviews.

· Each tool focuses on only a limited number of data elements (ranges from one to seven). Most of the existing tools focus on the PICO information (e.g. number of participants, their age, sex, country, recruiting centres, intervention groups, outcomes, and time points). A few are able to extract study design and results (e.g. objectives, study duration, participant flow), and two extract risk of bias information (Marshall et al 2016, Millard et al 2016). To date, well over half of the data elements needed for systematic reviews have not been explored for automated extraction.

  • Most tools highlight the sentence(s) that may contain the data elements as opposed to directly recording these data elements into a data collection form or a data system.
  • There is no gold standard or common dataset to evaluate the performance of these tools, limiting our ability to interpret the significance of the reported accuracy measures.

At the time of writing, we cannot recommend a specific tool for automating data extraction for routine systematic review production. There is a need for review authors to work with experts in informatics to refine these tools and evaluate them rigorously. Such investigations should address how the tool will fit into existing workflows. For example, the automated or semi-automated data extraction approaches may first act as checks for manual data extraction before they can replace it.

5.5.10 Suspicions of scientific misconduct

Systematic review authors can uncover suspected misconduct in the published literature. Misconduct includes fabrication or falsification of data or results, plagiarism, and research that does not adhere to ethical norms. Review authors need to be aware of scientific misconduct because the inclusion of fraudulent material could undermine the reliability of a review’s findings. Plagiarism of results data in the form of duplicated publication (either by the same or by different authors) may, if undetected, lead to study participants being double counted in a synthesis.

It is preferable to identify potential problems before, rather than after, publication of the systematic review, so that readers are not misled. However, empirical evidence indicates that the extent to which systematic review authors explore misconduct varies widely (Elia et al 2016). Text-matching software and systems such as CrossCheck may be helpful for detecting plagiarism, but they can detect only matching text, so data tables or figures need to be inspected by hand or using other systems (e.g. to detect image manipulation). Lists of data such as in a meta-analysis can be a useful means of detecting duplicated studies. Furthermore, examination of baseline data can lead to suspicions of misconduct for an individual randomized trial (Carlisle et al 2015). For example, Al-Marzouki and colleagues concluded that a trial report was fabricated or falsified on the basis of highly unlikely baseline differences between two randomized groups (Al-Marzouki et al 2005).

Cochrane Review authors are advised to consult with Cochrane editors if cases of suspected misconduct are identified. Searching for comments, letters or retractions may uncover additional information. Sensitivity analyses can be used to determine whether the studies arousing suspicion are influential in the conclusions of the review. Guidance for editors for addressing suspected misconduct will be available from Cochrane’s Editorial Publishing and Policy Resource (see community.cochrane.org ). Further information is available from the Committee on Publication Ethics (COPE; publicationethics.org ), including a series of flowcharts on how to proceed if various types of misconduct are suspected. Cases should be followed up, typically including an approach to the editors of the journals in which suspect reports were published. It may be useful to write first to the primary investigators to request clarification of apparent inconsistencies or unusual observations.

Because investigations may take time, and institutions may not always be responsive (Wager 2011), articles suspected of being fraudulent should be classified as ‘awaiting assessment’. If a misconduct investigation indicates that the publication is unreliable, or if a publication is retracted, it should not be included in the systematic review, and the reason should be noted in the ‘excluded studies’ section.

5.5.11 Key points in planning and reporting data extraction

In summary, the methods section of both the protocol and the review should detail:

  • the data categories that are to be extracted;
  • how extracted data from each report will be verified (e.g. extraction by two review authors, independently);
  • whether data extraction is undertaken by content area experts, methodologists, or both;
  • pilot testing, training and existence of coding instructions for the data collection form;
  • how data are extracted from multiple reports from the same study; and
  • how disagreements are handled when more than one author extracts data from each report.

5.6 Extracting study results and converting to the desired format

In most cases, it is desirable to collect summary data separately for each intervention group of interest and to enter these into software in which effect estimates can be calculated, such as RevMan. Sometimes the required data may be obtained only indirectly, and the relevant results may not be obvious. Chapter 6 provides many useful tips and techniques to deal with common situations. When summary data cannot be obtained from each intervention group, or where it is important to use results of adjusted analyses (for example to account for correlations in crossover or cluster-randomized trials) effect estimates may be available directly.

5.7 Managing and sharing data

When data have been collected for each individual study, it is helpful to organize them into a comprehensive electronic format, such as a database or spreadsheet, before entering data into a meta-analysis or other synthesis. When data are collated electronically, all or a subset of them can easily be exported for cleaning, consistency checks and analysis.

Tabulation of collected information about studies can facilitate classification of studies into appropriate comparisons and subgroups. It also allows identification of comparable outcome measures and statistics across studies. It will often be necessary to perform calculations to obtain the required statistics for presentation or synthesis. It is important through this process to retain clear information on the provenance of the data, with a clear distinction between data from a source document and data obtained through calculations. Statistical conversions, for example from standard errors to standard deviations, ideally should be undertaken with a computer rather than using a hand calculator to maintain a permanent record of the original and calculated numbers as well as the actual calculations used.

Ideally, data only need to be extracted once and should be stored in a secure and stable location for future updates of the review, regardless of whether the original review authors or a different group of authors update the review (Ip et al 2012). Standardizing and sharing data collection tools as well as data management systems among review authors working in similar topic areas can streamline systematic review production. Review authors have the opportunity to work with trialists, journal editors, funders, regulators, and other stakeholders to make study data (e.g. CSRs, IPD, and any other form of study data) publicly available, increasing the transparency of research. When legal and ethical to do so, we encourage review authors to share the data used in their systematic reviews to reduce waste and to allow verification and reanalysis because data will not have to be extracted again for future use (Mayo-Wilson et al 2018).

5.8 Chapter information

Editors: Tianjing Li, Julian PT Higgins, Jonathan J Deeks

Acknowledgements: This chapter builds on earlier versions of the Handbook . For details of previous authors and editors of the Handbook , see Preface. Andrew Herxheimer, Nicki Jackson, Yoon Loke, Deirdre Price and Helen Thomas contributed text. Stephanie Taylor and Sonja Hood contributed suggestions for designing data collection forms. We are grateful to Judith Anzures, Mike Clarke, Miranda Cumpston and Peter Gøtzsche for helpful comments.

Funding: JPTH is a member of the National Institute for Health Research (NIHR) Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol. JJD received support from the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. JPTH received funding from National Institute for Health Research Senior Investigator award NF-SI-0617-10145. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.

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research study data collection

The Ultimate Guide to Qualitative Research - Part 1: The Basics

research study data collection

  • Introduction and overview
  • What is qualitative research?
  • What is qualitative data?
  • Examples of qualitative data
  • Qualitative vs. quantitative research
  • Mixed methods
  • Qualitative research preparation
  • Theoretical perspective
  • Theoretical framework
  • Literature reviews
  • Research question
  • Conceptual framework
  • Conceptual vs. theoretical framework
  • Introduction

Data in research

Data collection methods, challenges in data collection, using technology in data collection, data organization.

  • Qualitative research methods
  • Focus groups
  • Observational research
  • Case studies
  • Ethnographical research
  • Ethical considerations
  • Confidentiality and privacy
  • Power dynamics
  • Reflexivity

Data collection - What is it and why is it important?

The data collected for your study informs the analysis of your research. Gathering data in a transparent and thorough manner informs the rest of your research and makes it persuasive to your audience.

research study data collection

We will look at the data collection process, the methods of data collection that exist in quantitative and qualitative research , and the various issues around data in qualitative research.

When it comes to defining data, data can be any sort of information that people use to better understand the world around them. Having this information allows us to robustly draw and verify conclusions, as opposed to relying on blind guesses or thought exercises.

Necessity of data collection skills

Collecting data is critical to the fundamental objective of research as a vehicle to organize knowledge. While this may seem intuitive, it's important to acknowledge that researchers must be as skilled in data collection as they are in data analysis .

Collecting the right data

Rather than just collecting as much data as possible, it's important to collect data that is relevant for answering your research question . Imagine a simple research question: what factors do people consider when buying a car? It would not be possible to ask every living person about their car purchases. Even if it was possible, not everyone drives a car, so asking non-drivers seems unproductive. As a result, the researcher conducting a study to devise data reports and marketing strategies has to take a sample of the relevant data to ensure reliable analysis and findings.

Data collection examples

In the broadest terms, any sort of data gathering contributes to the research process. In any work of science, researchers cannot make empirical conclusions without relying on some body of data to make rational judgments.

Various examples of data collection in the social sciences include:

  • responses to a survey about product satisfaction
  • interviews with students about their career goals
  • reactions to an experimental vitamin supplement regimen
  • observations of workplace interactions and practices
  • focus group data about customer behavior

Data science and scholarly research have almost limitless possibilities to collect data, and the primary requirement is that the dataset should be relevant to the research question and clearly defined. Researchers thus need to rule out any irrelevant data so that they can develop new theory or key findings.

Types of data

Researchers can collect data themselves (primary data) or use third-party data (secondary data). The data collection considerations regarding which type of data to work with have a direct relationship to your research question and objectives.

Primary data

Original research relies on first-party data, or primary data that the researcher collects themselves for their own analysis. When you are collecting information in a primary study yourself, you are more likely to gain the high quality you require.

Because the researcher is most aware of the inquiry they want to conduct and has tailored the research process to their inquiry, first-party data collection has the greatest potential for congruence between the data collected and the potential to generate relevant insights.

Ethnographic research , for example, relies on first-party data collection since a description of a culture or a group of people is contextualized through a comprehensive understanding of the researcher and their relative positioning to that culture.

Secondary data

Researchers can also use publicly available secondary data that other researchers have generated to analyze following a different approach and thus produce new insights. Online databases and literature reviews are good examples where researchers can find existing data to conduct research on a previously unexplored inquiry. However, it is important to consider data accuracy or relevance when using third-party data, given that the researcher can only conduct limited quality control of data that has already been collected.

research study data collection

A relatively new consideration in data collection and data analysis has been the advent of big data, where data scientists employ automated processes to collect data in large amounts.

research study data collection

The advantage of collecting data at scale is that a thorough analysis of a greater scope of data can potentially generate more generalizable findings. Nonetheless, this is a daunting task because it is time-consuming and arduous. Moreover, it requires skilled data scientists to sift through large data sets to filter out irrelevant data and generate useful insights. On the other hand, it is important for qualitative researchers to carefully consider their needs for data breadth versus depth: Qualitative studies typically rely on a relatively small number of participants but very detailed data is collected for each participant, because understanding the specific context and individual interpretations or experiences is often of central importance. When using big data, this depth of data is usually replaced with a greater breadth of data that includes a much greater number of participants. Researchers need to consider their need for depth or breadth to decide which data collection method is best suited to answer their research question.

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Different data collection procedures for gathering data exist depending on the research inquiry you want to conduct. Let's explore the common data collection methods in quantitative and qualitative research.

Quantitative data collection methods

Quantitative methods are used to collect numerical or quantifiable data. These can then be processed statistically to test hypotheses and gain insights. Quantitative data gathering is typically aimed at measuring a particular phenomenon (e.g., the amount of awareness a brand has in the market, the efficacy of a particular diet, etc.) in order to test hypotheses (e.g., social media marketing campaigns increase brand awareness, eating more fruits and vegetables leads to better physical performance, etc.).

research study data collection

Some qualitative methods of research can contribute to quantitative data collection and analysis. Online surveys and questionnaires with multiple-choice questions can produce structured data ready to be analyzed. A survey platform like Qualtrics, for example, aggregates survey responses in a spreadsheet to allow for numerical or frequency analysis.

Qualitative data collection methods

Analyzing qualitative data is important for describing a phenomenon (e.g., the requirements for good teaching practices), which may lead to the creation of propositions or the development of a theory. Behavioral data, transactional data, and data from social media monitoring are examples of different forms of data that can be collected qualitatively.

Consideration of tools or equipment for collecting data is also important. Primary data collection methods in observational research , for example, employ tools such as audio and video recorders , notebooks for writing field notes , and cameras for taking photographs. As long as the products of such tools can be analyzed, those products can be incorporated into a study's data collection.

Employing multiple data collection methods

Moreover, qualitative researchers seldom rely on one data collection method alone. Ethnographic researchers , in particular, can incorporate direct observation , interviews , focus group sessions , and document collection in their data collection process to produce the most contextualized data for their research. Mixed methods research employs multiple data collection methods, including qualitative and quantitative data, along with multiple tools to study a phenomenon from as many different angles as possible.

research study data collection

New forms of data collection

External data sources such as social media data and big data have also gained contemporary focus as social trends change and new research questions emerge. This has prompted the creation of novel data collection methods in research.

Ultimately, there are countless data collection instruments used for qualitative methods, but the key objective is to be able to produce relevant data that can be systematically analyzed. As a result, researchers can analyze audio, video, images, and other formats beyond text. As our world is continuously changing, for example, with the growing prominence of generative artificial intelligence and social media, researchers will undoubtedly bring forth new inquiries that require continuous innovation and adaptation with data collection methods.

research study data collection

Collecting data for qualitative research is a complex process that often comes with unique challenges. This section discusses some of the common obstacles that researchers may encounter during data collection and offers strategies to navigate these issues.

Access to participants

Obtaining access to research participants can be a significant challenge. This might be due to geographical distance, time constraints, or reluctance from potential participants. To address this, researchers need to clearly communicate the purpose of their study, ensure confidentiality, and be flexible with their scheduling.

Cultural and language barriers

Researchers may face cultural and language barriers, particularly in cross-cultural research. These barriers can affect communication and understanding between the researcher and the participant. Employing translators, cultural mediators, or learning the local language can be beneficial in overcoming these barriers.

research study data collection

Non-responsive or uncooperative participants

At times, researchers might encounter participants who are unwilling or unable to provide the required information. In these situations, rapport-building is crucial. The researcher should aim to build trust, create a comfortable environment for the participant, and reassure them about the confidentiality of their responses.

Time constraints

Qualitative research can be time-consuming, particularly when involving interviews or focus groups that require coordination of multiple schedules, transcription , and in-depth analysis . Adequate planning and organization can help mitigate this challenge.

Bias in data collection

Bias in data collection can occur when the researcher's preconceptions or the participant's desire to present themselves favorably affect the data. Strategies for mitigating bias include reflexivity , triangulation, and member checking .

Handling sensitive topics

Research involving sensitive topics can be challenging for both the researcher and the participant. Ensuring a safe and supportive environment , practicing empathetic listening, and providing resources for emotional support can help navigate these sensitive issues.

research study data collection

Collecting data in qualitative research can be a very rewarding but challenging experience. However, with careful planning, ethical conduct, and a flexible approach, researchers can effectively navigate these obstacles and collect robust, meaningful data.

Considerations when collecting data

Research relies on empiricism and credibility at all stages of a research inquiry. As a result, there are various data collection problems and issues that researchers need to keep in mind.

Data quality issues

Your analysis may depend on capturing the fine-grained details that some data collection tools may miss. In that case, you should carefully consider data quality issues regarding the precision of your data collection. For example, think about a picture taken with a smartphone camera and a picture taken with a professional camera. If you need high-resolution photos, it would make sense to rely on a professional camera that can provide adequate data quality.

Quantitative data collection often relies on precise data collection tools to evaluate outcomes, but researchers collecting qualitative data should also be concerned with quality assurance. For example, suppose a study involving direct observation requires multiple observers in different contexts. In that case, researchers should take care to ensure that all observers can gather data in a similar fashion to ensure that all data can be analyzed in the same way.

research study data collection

Data quality is a crucial consideration when gathering information. Even if the researcher has chosen an appropriate method for data collection, is the data that they collect useful and detailed enough to provide the necessary analysis to answer the given research inquiry?

One example where data quality is consequential in qualitative data collection includes interviews and focus groups. Recordings may lose some of the finer details of social interaction, such as pauses, thinking words, or utterances that aren't loud enough for the microphone to pick up.

Suppose you are conducting an interview for a study where such details are relevant to your analysis. In that case, you should consider employing tools that collect sufficiently rich data to record these aspects of interaction.

Data integrity

The possibility of inaccurate data has the potential to confound the data analysis process, as drawing conclusions or making decisions becomes difficult, if not impossible, with low-quality data. Failure to establish the integrity of data collection can cast doubt on the findings of a given study. Accurate data collection is just one aspect researchers should consider to protect data integrity. After that, it is a matter of preserving the data after data collection. How is the data stored? Who has access to the collected data? To what extent can the data be changed between data collection and research dissemination?

Data integrity is an issue of research ethics as well as research credibility . The researcher needs to establish that the data presented for research dissemination is an accurate representation of the phenomenon under study.

Imagine if a photograph of wildlife becomes so aged that the color becomes distorted over time. Suppose the findings depend on describing the colors of a particular animal or plant. In that case, then not preserving the integrity of the data presents a serious threat to the credibility of the research and the researcher. In addition, when transcribing an interview or focus group, it is important to take care that participants’ words are accurately transcribed to avoid unintentionally changing the data.

Transparency

As explored earlier, researchers rely on both intuition and data to make interpretations about the world. As a result, researchers have an obligation to explain how they collected data and describe their data so that audiences can also understand it. Establishing research transparency also allows other researchers to examine a study and determine if they find it credible and how they can continue to build off it.

To address this need, research papers typically have a methodology section, which includes descriptions of the tools employed for data collection and the breadth and depth of the data that is collected for the study. It is important to transparently convey every aspect of the data collection and analysis , which might involve providing a sample of the questions participants were asked, demographic information about participants, or proof of compliance with ethical standards, to name a few examples.

Subjectivity

How to gather data is also a key concern, especially in social sciences where people's perspectives represent the collected data, and these perspectives can vastly differ.

research study data collection

In interviews and focus groups, how questions are framed may change the nature of the answers that participants provide. In market research, researchers have to carefully design questions to not inadvertently lead customers to provide a certain response or to facilitate useful feedback. Even in the natural sciences, researchers have to regularly check whether the data collection equipment they use for gathering data is producing accurate data sets for analysis.

Finally, the different methods of data collection raise questions about whether the data says what we think it says. Consider how people might establish monitoring systems to track behavioral data online. When a user spends a certain amount of time on a mobile app, are they deeply engaged in using the app, or are they leaving it on while they work on other tasks?

Data collection is only as useful as the extent to which the resulting data can be systematically analyzed and is relevant to the research inquiry being pursued. While it is tempting to collect as much data as possible, it is the researcher’s analyses and inferences, not just the quantity of data, that ultimately determine the impact of the research.

Validity and reliability in qualitative data

Ensuring validity and reliability in qualitative data collection is paramount to producing meaningful, rigorous, and trustworthy research findings. This section will outline the core principles of validity and reliability, which stem from quantitative research, and then we will consider relevant quality criteria for qualitative research.

Understanding validity

In general terms, validity is about ensuring that the research accurately reflects the phenomena it purports to represent. It is tied to how well the methods and techniques used in a study align with the intended research question and how accurately the findings represent the participants' experiences or perceptions. In qualitative research, however, the co-existence of multiple realities is often recognized, rather than believing there is only one “true” reality out there that can be measured. Thus, qualitative researchers can instead convey credibility by transparently communicating their research question, operationalization of key concepts, and how this translated into their data collection instruments and analysis. Moreover, qualitative researchers should pay attention to whether their own preconceptions or goals might be inadvertently shaping their findings. In addition, potential reactivity effects can be considered, to assess how the research may have influenced their participants or research setting while collecting data.

Understanding reliability

Reliability broadly refers to the consistency of the research approach across different contexts and with different researchers. A quantitative study is considered reliable if its findings can be replicated in a similar context or if the same results can be obtained by a different researcher following the same research procedure.

In qualitative research, however, researchers acknowledge and embrace the specific context of their data and analysis. All knowledge that is generated is context-specific, so rather than claiming that a study’s findings can be reliably reproduced in a wholly different context, qualitative researchers aim to demonstrate the trustworthiness or dependability of their data and findings. Transparent descriptions and clear communication can convey to audiences that the research was conducted with rigor and coherence between the research question , methods, and findings, all of which can bolster the credibility of the qualitative study.

research study data collection

Enhancing data quality

Various strategies can be used to enhance data quality in qualitative research. Among them are:

1. Triangulation: This involves using multiple data sources, methods, or researchers to gather data about the same phenomenon. This can help to ensure the findings are robust and not dependent on a single source. 2. Member checking: This method involves returning the findings to the participants to check if the interpretations accurately reflect their experiences or perceptions. This can help to ensure the validity of the research findings. 3. Thick description: Providing detailed accounts of the context, interactions, and interpretations in the research report can allow others to understand the research process better, which is important to foster the communicability of one’s research. 4. Audit trail: Keeping a detailed record of the research process, decisions, and reflections can increase the transparency and coherence of the study.

research study data collection

A wide variety of technologies can be used to work with qualitative data. Technology not only aids in data collection but also in the organization , analysis , and presentation of data .

This section explores some of the key ways that technology can be integrated into qualitative data collection.

Digital tools for data collection

Digital tools can vastly improve the efficiency and effectiveness of data collection. For example, audio and video recording devices can capture interviews , focus groups , and observational data with great detail.

research study data collection

Online surveys and questionnaires can reach a wider audience, often at a lower cost and with quicker turnaround times compared with traditional methods. Mobile applications can also be used to capture real-time experiences, emotions, and activities through diary studies or experience sampling.

Online platforms for qualitative research

Online platforms like social media , blogs, and discussion forums provide a rich source of qualitative data. Researchers can analyze these platforms for insights into people's behaviors, attitudes, and experiences.

In addition, virtual communities and digital ethnography are becoming increasingly common as researchers explore these online spaces.

Ethical considerations with technology

With the increased use of technology, researchers must be mindful of ethical considerations , including privacy and consent . It's important to secure informed consent when collecting data from online platforms or using digital tools, and all researchers should obtain the necessary approvals for collecting data and adhering to any applicable codes of conduct (such as GDPR). It's also crucial to ensure data security and confidentiality when storing data on digital platforms.

Advantages and limitations of technology

While technology offers numerous advantages in terms of efficiency, accessibility, and breadth of data, it also presents limitations. For example, digital tools may not capture the full nuance and richness of face-to-face interactions.

Furthermore, technological glitches and data loss are potential risks. Therefore, it's important for researchers to understand these trade-offs when incorporating technology into their data collection process.

As technology continues to evolve, so too will its applications in qualitative research. Embracing these technological advancements can help researchers to enhance their data collection practices, offering new opportunities for capturing, analyzing , and presenting qualitative data .

Data analysis after collecting data is only possible if the data is sufficiently organized into a form that can be easily sorted and understood. Imagine collecting social media data , which could be millions of posts from millions of social media users every day. You can dump every single post into a file, but how can you make sense of it?

Data organization is especially important when dealing with unstructured data. The researcher needs to structure the data in some way that facilitates the analytical process.

Transcription

Collecting data in focus groups, interviews, or other similar interactions produces raw video and audio recordings . This data can often be analyzed for contextual cues such as non-verbal interaction, facial expressions, and accents. However, most traditional analyses of interview and focus group data benefit from converting participants’ words into text.

Recordings are typically transcribed so that the text can be systematically analyzed and incorporated into research papers or presentations . Transcription can be a tedious task, especially if a researcher has to deal with hours of audio data. These days, researchers can often choose between manually transcribing their raw data or using automated transcription services to greatly speed up this process.

Survey data

In online survey platforms, participant responses to closed-ended questions can be easily aggregated in a spreadsheet. Responses to any open-ended questions can also be included in a spreadsheet or saved as separate files for subsequent analysis of the text participants wrote. Since survey data is relatively structured, it tends to be quicker and easier to organize than other forms of qualitative data that are more unstructured, such as interviews or observations.

Field notes and artifacts

In ethnographic research or research involving direct observation , gathering data often means writing notes or taking photographs during field work. While field notes can be typed into a document for data analysis, the researcher can also scan their notes into an image or a PDF for later organization.

This degree of flexibility allows researchers to code all forms of data that aren't textual in nature but can still provide useful data points for analysis and theoretical development.

Coding is among the most fundamental skills in qualitative research, because coding is how researchers can effectively reduce large datasets into a series of compact codes for later analysis. If you are dealing with dozens or hundreds of pages of qualitative data, then applying codes to your data is a key method for condensing, synthesizing, and understanding the data.

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Data Collection Methods: Types & Examples

Data Collection Methods

Data is a collection of facts, figures, objects, symbols, and events gathered from different sources. Organizations collect data using various methods to make better decisions. Without data, it would be difficult for organizations to make appropriate decisions, so data is collected from different audiences at various times.

For example, an organization must collect data on product demand, customer preferences, and competitors before launching a new product. If data is not collected beforehand, the organization’s newly launched product may fail for many reasons, such as less demand and inability to meet customer needs. 

Although data is a valuable asset for every organization, it does not serve any purpose until it is analyzed or processed to achieve the desired results.

What are Data Collection Methods?

Data collection methods are techniques and procedures for gathering information for research purposes. They can range from simple self-reported surveys to more complex quantitative or qualitative experiments.

Some common data collection methods include surveys , interviews, observations, focus groups, experiments, and secondary data analysis . The data collected through these methods can then be analyzed and used to support or refute research hypotheses and draw conclusions about the study’s subject matter.

Understanding Data Collection Methods

Data collection methods encompass a variety of techniques and tools for gathering quantitative and qualitative data. These methods are integral to the data collection process and ensure accurate and comprehensive data acquisition. 

Quantitative data collection methods involve systematic approaches to collecting data, like numerical data, such as surveys, polls, and statistical analysis, aimed at quantifying phenomena and trends. 

Conversely, qualitative data collection methods focus on capturing non-numerical information, such as interviews, focus groups, and observations, to delve deeper into understanding attitudes, behaviors, and motivations. 

Combining quantitative and qualitative data collection techniques can enrich organizations’ datasets and gain comprehensive insights into complex phenomena.

Effective utilization of accurate data collection tools and techniques enhances the accuracy and reliability of collected data, facilitating informed decision-making and strategic planning.

LEARN ABOUT: Self-Selection Bias

Importance of Data Collection Methods

Data collection methods play a crucial role in the research process as they determine the quality and accuracy of the data collected. Here are some major importance of data collection methods.

  • Quality and Accuracy: The choice of data collection technique directly impacts the quality and accuracy of the data obtained. Properly designed methods help ensure that the data collected is error-free and relevant to the research questions.
  • Relevance, Validity, and Reliability: Effective data collection methods help ensure that the data collected is relevant to the research objectives, valid (measuring what it intends to measure), and reliable (consistent and reproducible).
  • Bias Reduction and Representativeness: Carefully chosen data collection methods can help minimize biases inherent in the research process, such as sampling bias or response bias. They also aid in achieving a representative sample, enhancing the findings’ generalizability.
  • Informed Decision Making: Accurate and reliable data collected through appropriate methods provide a solid foundation for making informed decisions based on research findings. This is crucial for both academic research and practical applications in various fields.
  • Achievement of Research Objectives: Data collection methods should align with the research objectives to ensure that the collected data effectively addresses the research questions or hypotheses. Properly collected data facilitates the attainment of these objectives.
  • Support for Validity and Reliability: Validity and reliability are essential to research validity. The choice of data collection methods can either enhance or detract from the validity and reliability of research findings. Therefore, selecting appropriate methods is critical for ensuring the credibility of the research.

The importance of data collection methods cannot be overstated, as they play a key role in the research study’s overall success and internal validity .

Types of Data Collection Methods

The choice of data collection method depends on the research question being addressed, the type of data needed, and the resources and time available. Data collection methods can be categorized into primary and secondary methods.

1. Primary Data Collection Methods

Primary data is collected from first-hand experience and is not used in the past. The data gathered by primary data collection methods are highly accurate and specific to the research’s motive.

Primary data collection methods can be divided into two categories: quantitative methods and qualitative methods .

Quantitative Methods:

Quantitative techniques for market research and demand forecasting usually use statistical tools. In these techniques, demand is forecasted based on historical data. These methods of primary data collection are generally used to make long-term forecasts. Statistical analysis methods are highly reliable as subjectivity is minimal.

research study data collection

  • Time Series Analysis: A time series refers to a sequential order of values of a variable, known as a trend, at equal time intervals. Using patterns, an organization can predict the demand for its products and services over a projected time period. 
  • Smoothing Techniques: Smoothing techniques can be used in cases where the time series lacks significant trends. They eliminate random variation from the historical demand, helping identify patterns and demand levels to estimate future demand.  The most common methods used in smoothing demand forecasting are the simple moving average and weighted moving average methods. 
  • Barometric Method: Also known as the leading indicators approach, researchers use this method to speculate future trends based on current developments. When past events are considered to predict future events, they act as leading indicators.

Qualitative Methods:

Qualitative data collection methods are especially useful when historical data is unavailable or when numbers or mathematical calculations are unnecessary.

Qualitative research is closely associated with words, sounds, feelings, emotions, colors, and non-quantifiable elements. These techniques are based on experience, judgment, intuition, conjecture, emotion, etc.

Quantitative methods do not provide the motive behind participants’ responses, often don’t reach underrepresented populations, and require long periods of time to collect the data. Hence, it is best to combine quantitative methods with qualitative methods.

1. Surveys: Surveys collect data from the target audience and gather insights into their preferences, opinions, choices, and feedback related to their products and services. Most survey software offers a wide range of question types.

You can also use a ready-made survey template to save time and effort. Online surveys can be customized to match the business’s brand by changing the theme, logo, etc. They can be distributed through several channels, such as email, website, offline app, QR code, social media, etc. 

You can select the channel based on your audience’s type and source. Once the data is collected, survey software can generate various reports and run analytics algorithms to discover hidden insights. 

A survey dashboard can give you statistics related to response rate, completion rate, demographics-based filters, export and sharing options, etc. Integrating survey builders with third-party apps can maximize the effort spent on online real-time data collection . 

Practical business intelligence relies on the synergy between analytics and reporting , where analytics uncovers valuable insights, and reporting communicates these findings to stakeholders.

2. Polls: Polls comprise one single or multiple-choice question . They are useful when you need to get a quick pulse of the audience’s sentiments. Because they are short, it is easier to get responses from people.

Like surveys, online polls can be embedded into various platforms. Once the respondents answer the question, they can also be shown how they compare to others’ responses.

Interviews: In this method, the interviewer asks the respondents face-to-face or by telephone. 

3. Interviews: In face-to-face interviews, the interviewer asks a series of questions to the interviewee in person and notes down responses. If it is not feasible to meet the person, the interviewer can go for a telephone interview. 

This form of data collection is suitable for only a few respondents. It is too time-consuming and tedious to repeat the same process if there are many participants.

research study data collection

4. Delphi Technique: In the Delphi method, market experts are provided with the estimates and assumptions of other industry experts’ forecasts. Experts may reconsider and revise their estimates and assumptions based on this information. The consensus of all experts on demand forecasts constitutes the final demand forecast.

5. Focus Groups: Focus groups are one example of qualitative data in education . In a focus group, a small group of people, around 8-10 members, discuss the common areas of the research problem. Each individual provides his or her insights on the issue concerned. 

A moderator regulates the discussion among the group members. At the end of the discussion, the group reaches a consensus.

6. Questionnaire: A questionnaire is a printed set of open-ended or closed-ended questions that respondents must answer based on their knowledge and experience with the issue. The questionnaire is part of the survey, whereas the questionnaire’s end goal may or may not be a survey.

2. Secondary Data Collection Methods

Secondary data is data that has been used in the past. The researcher can obtain data from the data sources , both internal and external, to the organizational data . 

Internal sources of secondary data:

  • Organization’s health and safety records
  • Mission and vision statements
  • Financial Statements
  • Sales Report
  • CRM Software
  • Executive summaries

External sources of secondary data:

  • Government reports
  • Press releases
  • Business journals

Secondary data collection methods can also involve quantitative and qualitative techniques. Secondary data is easily available, less time-consuming, and expensive than primary data. However, the authenticity of the data gathered cannot be verified using these methods.

Secondary data collection methods can also involve quantitative and qualitative observation techniques. Secondary data is easily available, less time-consuming, and more expensive than primary data. 

However, the authenticity of the data gathered cannot be verified using these methods.

Regardless of the data collection method of your choice, there must be direct communication with decision-makers so that they understand and commit to acting according to the results.

For this reason, we must pay special attention to the analysis and presentation of the information obtained. Remember that these data must be useful and functional to us, so the data collection method has much to do with it.

LEARN ABOUT: Data Asset Management

How Can QuestionPro Help to Create Effective Data Collection?

QuestionPro is a comprehensive online survey software platform that can greatly assist in various data collection methods. Here’s how it can help:

  • Survey Creation: QuestionPro offers a user-friendly interface for creating surveys with various question types, including multiple-choice, open-ended, Likert scale, and more. Researchers can customize surveys to fit their specific research needs and objectives.
  • Diverse Distribution Channels: The platform provides multiple channels for distributing surveys, including email, web links, social media, and website embedding surveys. This enables researchers to reach a wide audience and collect data efficiently.
  • Panel Management: QuestionPro offers panel management features, allowing researchers to create and manage panels of respondents for targeted data collection. This is particularly useful for longitudinal studies or when targeting specific demographics.
  • Data Analysis Tools: The platform includes robust data analysis tools that enable researchers to analyze survey responses in real-time. Researchers can generate customizable reports, visualize data through charts and graphs, and identify trends and patterns within the data.
  • Data Security and Compliance: QuestionPro prioritizes data security and compliance with regulations such as GDPR and HIPAA. The platform offers features such as SSL encryption, data masking, and secure data storage to ensure the confidentiality and integrity of collected data.
  • Mobile Compatibility: With the increasing use of mobile devices, QuestionPro ensures that surveys are mobile-responsive, allowing respondents to participate in surveys conveniently from their smartphones or tablets.
  • Integration Capabilities: QuestionPro integrates with various third-party tools and platforms, including CRMs, email marketing software, and analytics tools. This allows researchers to streamline their data collection processes and incorporate survey data into their existing workflows.
  • Customization and Branding: Researchers can customize surveys with their branding elements, such as logos, colors, and themes, enhancing the professional appearance of surveys and increasing respondent engagement.

The conclusion you obtain from your investigation will set the course of the company’s decision-making, so present your report clearly and list the steps you followed to obtain those results.

Make sure that whoever will take the corresponding actions understands the importance of the information collected and that it gives them the solutions they expect.

QuestionPro offers a comprehensive suite of features and tools that can significantly streamline the data collection process, from survey creation to analysis, while ensuring data security and compliance. Remember that at QuestionPro, we can help you collect data easily and efficiently. Request a demo and learn about all the tools we have for you.

Frequently Asked Questions (FAQs)

A: Common methods include surveys, interviews, observations, focus groups, and experiments.

A: Data collection helps organizations make informed decisions and understand trends, customer preferences, and market demands.

A: Quantitative methods focus on numerical data and statistical analysis, while qualitative methods explore non-numerical insights like attitudes and behaviors.

A: Yes, combining methods can provide a more comprehensive understanding of the research topic.

A: Technology streamlines data collection with tools like online surveys, mobile data gathering, and integrated analytics platforms.

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Research-Methodology

Data Collection Methods

Data collection is a process of collecting information from all the relevant sources to find answers to the research problem, test the hypothesis (if you are following deductive approach ) and evaluate the outcomes. Data collection methods can be divided into two categories: secondary methods of data collection and primary methods of data collection.

Secondary Data Collection Methods

Secondary data is a type of data that has already been published in books, newspapers, magazines, journals, online portals etc.  There is an abundance of data available in these sources about your research area in business studies, almost regardless of the nature of the research area. Therefore, application of appropriate set of criteria to select secondary data to be used in the study plays an important role in terms of increasing the levels of research validity and reliability.

These criteria include, but not limited to date of publication, credential of the author, reliability of the source, quality of discussions, depth of analyses, the extent of contribution of the text to the development of the research area etc. Secondary data collection is discussed in greater depth in Literature Review chapter.

Secondary data collection methods offer a range of advantages such as saving time, effort and expenses. However they have a major disadvantage. Specifically, secondary research does not make contribution to the expansion of the literature by producing fresh (new) data.

Primary Data Collection Methods

Primary data is the type of data that has not been around before. Primary data is unique findings of your research. Primary data collection and analysis typically requires more time and effort to conduct compared to the secondary data research. Primary data collection methods can be divided into two groups: quantitative and qualitative.

Quantitative data collection methods are based on mathematical calculations in various formats. Methods of quantitative data collection and analysis include questionnaires with closed-ended questions, methods of correlation and regression, mean, mode and median and others.

Quantitative methods are cheaper to apply and they can be applied within shorter duration of time compared to qualitative methods. Moreover, due to a high level of standardisation of quantitative methods, it is easy to make comparisons of findings.

Qualitative research methods , on the contrary, do not involve numbers or mathematical calculations. Qualitative research is closely associated with words, sounds, feeling, emotions, colours and other elements that are non-quantifiable.

Qualitative studies aim to ensure greater level of depth of understanding and qualitative data collection methods include interviews, questionnaires with open-ended questions, focus groups, observation, game or role-playing, case studies etc.

Your choice between quantitative or qualitative methods of data collection depends on the area of your research and the nature of research aims and objectives.

My e-book, The Ultimate Guide to Writing a Dissertation in Business Studies: a step by step assistance offers practical assistance to complete a dissertation with minimum or no stress. The e-book covers all stages of writing a dissertation starting from the selection to the research area to submitting the completed version of the work within the deadline.

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Data Collection Methods

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  • Data Collection Methods | Step-by-Step Guide & Examples

Data Collection Methods | Step-by-Step Guide & Examples

Published on 4 May 2022 by Pritha Bhandari .

Data collection is a systematic process of gathering observations or measurements. Whether you are performing research for business, governmental, or academic purposes, data collection allows you to gain first-hand knowledge and original insights into your research problem .

While methods and aims may differ between fields, the overall process of data collection remains largely the same. Before you begin collecting data, you need to consider:

  • The  aim of the research
  • The type of data that you will collect
  • The methods and procedures you will use to collect, store, and process the data

To collect high-quality data that is relevant to your purposes, follow these four steps.

Table of contents

Step 1: define the aim of your research, step 2: choose your data collection method, step 3: plan your data collection procedures, step 4: collect the data, frequently asked questions about data collection.

Before you start the process of data collection, you need to identify exactly what you want to achieve. You can start by writing a problem statement : what is the practical or scientific issue that you want to address, and why does it matter?

Next, formulate one or more research questions that precisely define what you want to find out. Depending on your research questions, you might need to collect quantitative or qualitative data :

  • Quantitative data is expressed in numbers and graphs and is analysed through statistical methods .
  • Qualitative data is expressed in words and analysed through interpretations and categorisations.

If your aim is to test a hypothesis , measure something precisely, or gain large-scale statistical insights, collect quantitative data. If your aim is to explore ideas, understand experiences, or gain detailed insights into a specific context, collect qualitative data.

If you have several aims, you can use a mixed methods approach that collects both types of data.

  • Your first aim is to assess whether there are significant differences in perceptions of managers across different departments and office locations.
  • Your second aim is to gather meaningful feedback from employees to explore new ideas for how managers can improve.

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Based on the data you want to collect, decide which method is best suited for your research.

  • Experimental research is primarily a quantitative method.
  • Interviews , focus groups , and ethnographies are qualitative methods.
  • Surveys , observations, archival research, and secondary data collection can be quantitative or qualitative methods.

Carefully consider what method you will use to gather data that helps you directly answer your research questions.

Data collection methods
Method When to use How to collect data
Experiment To test a causal relationship. Manipulate variables and measure their effects on others.
Survey To understand the general characteristics or opinions of a group of people. Distribute a list of questions to a sample online, in person, or over the phone.
Interview/focus group To gain an in-depth understanding of perceptions or opinions on a topic. Verbally ask participants open-ended questions in individual interviews or focus group discussions.
Observation To understand something in its natural setting. Measure or survey a sample without trying to affect them.
Ethnography To study the culture of a community or organisation first-hand. Join and participate in a community and record your observations and reflections.
Archival research To understand current or historical events, conditions, or practices. Access manuscripts, documents, or records from libraries, depositories, or the internet.
Secondary data collection To analyse data from populations that you can’t access first-hand. Find existing datasets that have already been collected, from sources such as government agencies or research organisations.

When you know which method(s) you are using, you need to plan exactly how you will implement them. What procedures will you follow to make accurate observations or measurements of the variables you are interested in?

For instance, if you’re conducting surveys or interviews, decide what form the questions will take; if you’re conducting an experiment, make decisions about your experimental design .

Operationalisation

Sometimes your variables can be measured directly: for example, you can collect data on the average age of employees simply by asking for dates of birth. However, often you’ll be interested in collecting data on more abstract concepts or variables that can’t be directly observed.

Operationalisation means turning abstract conceptual ideas into measurable observations. When planning how you will collect data, you need to translate the conceptual definition of what you want to study into the operational definition of what you will actually measure.

  • You ask managers to rate their own leadership skills on 5-point scales assessing the ability to delegate, decisiveness, and dependability.
  • You ask their direct employees to provide anonymous feedback on the managers regarding the same topics.

You may need to develop a sampling plan to obtain data systematically. This involves defining a population , the group you want to draw conclusions about, and a sample, the group you will actually collect data from.

Your sampling method will determine how you recruit participants or obtain measurements for your study. To decide on a sampling method you will need to consider factors like the required sample size, accessibility of the sample, and time frame of the data collection.

Standardising procedures

If multiple researchers are involved, write a detailed manual to standardise data collection procedures in your study.

This means laying out specific step-by-step instructions so that everyone in your research team collects data in a consistent way – for example, by conducting experiments under the same conditions and using objective criteria to record and categorise observations.

This helps ensure the reliability of your data, and you can also use it to replicate the study in the future.

Creating a data management plan

Before beginning data collection, you should also decide how you will organise and store your data.

  • If you are collecting data from people, you will likely need to anonymise and safeguard the data to prevent leaks of sensitive information (e.g. names or identity numbers).
  • If you are collecting data via interviews or pencil-and-paper formats, you will need to perform transcriptions or data entry in systematic ways to minimise distortion.
  • You can prevent loss of data by having an organisation system that is routinely backed up.

Finally, you can implement your chosen methods to measure or observe the variables you are interested in.

The closed-ended questions ask participants to rate their manager’s leadership skills on scales from 1 to 5. The data produced is numerical and can be statistically analysed for averages and patterns.

To ensure that high-quality data is recorded in a systematic way, here are some best practices:

  • Record all relevant information as and when you obtain data. For example, note down whether or how lab equipment is recalibrated during an experimental study.
  • Double-check manual data entry for errors.
  • If you collect quantitative data, you can assess the reliability and validity to get an indication of your data quality.

Data collection is the systematic process by which observations or measurements are gathered in research. It is used in many different contexts by academics, governments, businesses, and other organisations.

When conducting research, collecting original data has significant advantages:

  • You can tailor data collection to your specific research aims (e.g., understanding the needs of your consumers or user testing your website).
  • You can control and standardise the process for high reliability and validity (e.g., choosing appropriate measurements and sampling methods ).

However, there are also some drawbacks: data collection can be time-consuming, labour-intensive, and expensive. In some cases, it’s more efficient to use secondary data that has already been collected by someone else, but the data might be less reliable.

Quantitative research deals with numbers and statistics, while qualitative research deals with words and meanings.

Quantitative methods allow you to test a hypothesis by systematically collecting and analysing data, while qualitative methods allow you to explore ideas and experiences in depth.

Reliability and validity are both about how well a method measures something:

  • Reliability refers to the  consistency of a measure (whether the results can be reproduced under the same conditions).
  • Validity   refers to the  accuracy of a measure (whether the results really do represent what they are supposed to measure).

If you are doing experimental research , you also have to consider the internal and external validity of your experiment.

In mixed methods research , you use both qualitative and quantitative data collection and analysis methods to answer your research question .

Operationalisation means turning abstract conceptual ideas into measurable observations.

For example, the concept of social anxiety isn’t directly observable, but it can be operationally defined in terms of self-rating scores, behavioural avoidance of crowded places, or physical anxiety symptoms in social situations.

Before collecting data , it’s important to consider how you will operationalise the variables that you want to measure.

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  • 7 Data Collection Methods & Tools For Research

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  • Data Collection

The underlying need for Data collection is to capture quality evidence that seeks to answer all the questions that have been posed. Through data collection businesses or management can deduce quality information that is a prerequisite for making informed decisions.

To improve the quality of information, it is expedient that data is collected so that you can draw inferences and make informed decisions on what is considered factual.

At the end of this article, you would understand why picking the best data collection method is necessary for achieving your set objective. 

Sign up on Formplus Builder to create your preferred online surveys or questionnaire for data collection. You don’t need to be tech-savvy! Start creating quality questionnaires with Formplus.

What is Data Collection?

Data collection is a methodical process of gathering and analyzing specific information to proffer solutions to relevant questions and evaluate the results. It focuses on finding out all there is to a particular subject matter. Data is collected to be further subjected to hypothesis testing which seeks to explain a phenomenon.

Hypothesis testing eliminates assumptions while making a proposition from the basis of reason.

research study data collection

For collectors of data, there is a range of outcomes for which the data is collected. But the key purpose for which data is collected is to put a researcher in a vantage position to make predictions about future probabilities and trends.

The core forms in which data can be collected are primary and secondary data. While the former is collected by a researcher through first-hand sources, the latter is collected by an individual other than the user. 

Types of Data Collection 

Before broaching the subject of the various types of data collection. It is pertinent to note that data collection in itself falls under two broad categories; Primary data collection and secondary data collection.

Primary Data Collection

Primary data collection by definition is the gathering of raw data collected at the source. It is a process of collecting the original data collected by a researcher for a specific research purpose. It could be further analyzed into two segments; qualitative research and quantitative data collection methods. 

  • Qualitative Research Method 

The qualitative research methods of data collection do not involve the collection of data that involves numbers or a need to be deduced through a mathematical calculation, rather it is based on the non-quantifiable elements like the feeling or emotion of the researcher. An example of such a method is an open-ended questionnaire.

research study data collection

  • Quantitative Method

Quantitative methods are presented in numbers and require a mathematical calculation to deduce. An example would be the use of a questionnaire with close-ended questions to arrive at figures to be calculated Mathematically. Also, methods of correlation and regression, mean, mode and median.

research study data collection

Read Also: 15 Reasons to Choose Quantitative over Qualitative Research

Secondary Data Collection

Secondary data collection, on the other hand, is referred to as the gathering of second-hand data collected by an individual who is not the original user. It is the process of collecting data that is already existing, be it already published books, journals, and/or online portals. In terms of ease, it is much less expensive and easier to collect.

Your choice between Primary data collection and secondary data collection depends on the nature, scope, and area of your research as well as its aims and objectives. 

Importance of Data Collection

There are a bunch of underlying reasons for collecting data, especially for a researcher. Walking you through them, here are a few reasons; 

  • Integrity of the Research

A key reason for collecting data, be it through quantitative or qualitative methods is to ensure that the integrity of the research question is indeed maintained.

  • Reduce the likelihood of errors

The correct use of appropriate data collection of methods reduces the likelihood of errors consistent with the results. 

  • Decision Making

To minimize the risk of errors in decision-making, it is important that accurate data is collected so that the researcher doesn’t make uninformed decisions. 

  • Save Cost and Time

Data collection saves the researcher time and funds that would otherwise be misspent without a deeper understanding of the topic or subject matter.

  • To support a need for a new idea, change, and/or innovation

To prove the need for a change in the norm or the introduction of new information that will be widely accepted, it is important to collect data as evidence to support these claims.

What is a Data Collection Tool?

Data collection tools refer to the devices/instruments used to collect data, such as a paper questionnaire or computer-assisted interviewing system. Case Studies, Checklists, Interviews, Observation sometimes, and Surveys or Questionnaires are all tools used to collect data.

It is important to decide on the tools for data collection because research is carried out in different ways and for different purposes. The objective behind data collection is to capture quality evidence that allows analysis to lead to the formulation of convincing and credible answers to the posed questions.

The objective behind data collection is to capture quality evidence that allows analysis to lead to the formulation of convincing and credible answers to the questions that have been posed – Click to Tweet

The Formplus online data collection tool is perfect for gathering primary data, i.e. raw data collected from the source. You can easily get data with at least three data collection methods with our online and offline data-gathering tool. I.e Online Questionnaires , Focus Groups, and Reporting. 

In our previous articles, we’ve explained why quantitative research methods are more effective than qualitative methods . However, with the Formplus data collection tool, you can gather all types of primary data for academic, opinion or product research.

Top Data Collection Methods and Tools for Academic, Opinion, or Product Research

The following are the top 7 data collection methods for Academic, Opinion-based, or product research. Also discussed in detail are the nature, pros, and cons of each one. At the end of this segment, you will be best informed about which method best suits your research. 

An interview is a face-to-face conversation between two individuals with the sole purpose of collecting relevant information to satisfy a research purpose. Interviews are of different types namely; Structured, Semi-structured , and unstructured with each having a slight variation from the other.

Use this interview consent form template to let an interviewee give you consent to use data gotten from your interviews for investigative research purposes.

  • Structured Interviews – Simply put, it is a verbally administered questionnaire. In terms of depth, it is surface level and is usually completed within a short period. For speed and efficiency, it is highly recommendable, but it lacks depth.
  • Semi-structured Interviews – In this method, there subsist several key questions which cover the scope of the areas to be explored. It allows a little more leeway for the researcher to explore the subject matter.
  • Unstructured Interviews – It is an in-depth interview that allows the researcher to collect a wide range of information with a purpose. An advantage of this method is the freedom it gives a researcher to combine structure with flexibility even though it is more time-consuming.
  • In-depth information
  • Freedom of flexibility
  • Accurate data.
  • Time-consuming
  • Expensive to collect.

What are The Best Data Collection Tools for Interviews? 

For collecting data through interviews, here are a few tools you can use to easily collect data.

  • Audio Recorder

An audio recorder is used for recording sound on disc, tape, or film. Audio information can meet the needs of a wide range of people, as well as provide alternatives to print data collection tools.

  • Digital Camera

An advantage of a digital camera is that it can be used for transmitting those images to a monitor screen when the need arises.

A camcorder is used for collecting data through interviews. It provides a combination of both an audio recorder and a video camera. The data provided is qualitative in nature and allows the respondents to answer questions asked exhaustively. If you need to collect sensitive information during an interview, a camcorder might not work for you as you would need to maintain your subject’s privacy.

Want to conduct an interview for qualitative data research or a special report? Use this online interview consent form template to allow the interviewee to give their consent before you use the interview data for research or report. With premium features like e-signature, upload fields, form security, etc., Formplus Builder is the perfect tool to create your preferred online consent forms without coding experience. 

  • QUESTIONNAIRES

This is the process of collecting data through an instrument consisting of a series of questions and prompts to receive a response from the individuals it is administered to. Questionnaires are designed to collect data from a group. 

For clarity, it is important to note that a questionnaire isn’t a survey, rather it forms a part of it. A survey is a process of data gathering involving a variety of data collection methods, including a questionnaire.

On a questionnaire, there are three kinds of questions used. They are; fixed-alternative, scale, and open-ended. With each of the questions tailored to the nature and scope of the research.

  • Can be administered in large numbers and is cost-effective.
  • It can be used to compare and contrast previous research to measure change.
  • Easy to visualize and analyze.
  • Questionnaires offer actionable data.
  • Respondent identity is protected.
  • Questionnaires can cover all areas of a topic.
  • Relatively inexpensive.
  • Answers may be dishonest or the respondents lose interest midway.
  • Questionnaires can’t produce qualitative data.
  • Questions might be left unanswered.
  • Respondents may have a hidden agenda.
  • Not all questions can be analyzed easily.

What are the Best Data Collection Tools for Questionnaires? 

  • Formplus Online Questionnaire

Formplus lets you create powerful forms to help you collect the information you need. Formplus helps you create the online forms that you like. The Formplus online questionnaire form template to get actionable trends and measurable responses. Conduct research, optimize knowledge of your brand or just get to know an audience with this form template. The form template is fast, free and fully customizable.

  • Paper Questionnaire

A paper questionnaire is a data collection tool consisting of a series of questions and/or prompts for the purpose of gathering information from respondents. Mostly designed for statistical analysis of the responses, they can also be used as a form of data collection.

By definition, data reporting is the process of gathering and submitting data to be further subjected to analysis. The key aspect of data reporting is reporting accurate data because inaccurate data reporting leads to uninformed decision-making.

  • Informed decision-making.
  • Easily accessible.
  • Self-reported answers may be exaggerated.
  • The results may be affected by bias.
  • Respondents may be too shy to give out all the details.
  • Inaccurate reports will lead to uninformed decisions.

What are the Best Data Collection Tools for Reporting?

Reporting tools enable you to extract and present data in charts, tables, and other visualizations so users can find useful information. You could source data for reporting from Non-Governmental Organizations (NGO) reports, newspapers, website articles, and hospital records.

  • NGO Reports

Contained in NGO report is an in-depth and comprehensive report on the activities carried out by the NGO, covering areas such as business and human rights. The information contained in these reports is research-specific and forms an acceptable academic base for collecting data. NGOs often focus on development projects which are organized to promote particular causes.

Newspaper data are relatively easy to collect and are sometimes the only continuously available source of event data. Even though there is a problem of bias in newspaper data, it is still a valid tool in collecting data for Reporting.

  • Website Articles

Gathering and using data contained in website articles is also another tool for data collection. Collecting data from web articles is a quicker and less expensive data collection Two major disadvantages of using this data reporting method are biases inherent in the data collection process and possible security/confidentiality concerns.

  • Hospital Care records

Health care involves a diverse set of public and private data collection systems, including health surveys, administrative enrollment and billing records, and medical records, used by various entities, including hospitals, CHCs, physicians, and health plans. The data provided is clear, unbiased and accurate, but must be obtained under legal means as medical data is kept with the strictest regulations.

  • EXISTING DATA

This is the introduction of new investigative questions in addition to/other than the ones originally used when the data was initially gathered. It involves adding measurement to a study or research. An example would be sourcing data from an archive.

  • Accuracy is very high.
  • Easily accessible information.
  • Problems with evaluation.
  • Difficulty in understanding.

What are the Best Data Collection Tools for Existing Data?

The concept of Existing data means that data is collected from existing sources to investigate research questions other than those for which the data were originally gathered. Tools to collect existing data include: 

  • Research Journals – Unlike newspapers and magazines, research journals are intended for an academic or technical audience, not general readers. A journal is a scholarly publication containing articles written by researchers, professors, and other experts.
  • Surveys – A survey is a data collection tool for gathering information from a sample population, with the intention of generalizing the results to a larger population. Surveys have a variety of purposes and can be carried out in many ways depending on the objectives to be achieved.
  • OBSERVATION

This is a data collection method by which information on a phenomenon is gathered through observation. The nature of the observation could be accomplished either as a complete observer, an observer as a participant, a participant as an observer, or as a complete participant. This method is a key base for formulating a hypothesis.

  • Easy to administer.
  • There subsists a greater accuracy with results.
  • It is a universally accepted practice.
  • It diffuses the situation of the unwillingness of respondents to administer a report.
  • It is appropriate for certain situations.
  • Some phenomena aren’t open to observation.
  • It cannot be relied upon.
  • Bias may arise.
  • It is expensive to administer.
  • Its validity cannot be predicted accurately.

What are the Best Data Collection Tools for Observation?

Observation involves the active acquisition of information from a primary source. Observation can also involve the perception and recording of data via the use of scientific instruments. The best tools for Observation are:

  • Checklists – state-specific criteria, that allow users to gather information and make judgments about what they should know in relation to the outcomes. They offer systematic ways of collecting data about specific behaviors, knowledge, and skills.
  • Direct observation – This is an observational study method of collecting evaluative information. The evaluator watches the subject in his or her usual environment without altering that environment.

FOCUS GROUPS

The opposite of quantitative research which involves numerical-based data, this data collection method focuses more on qualitative research. It falls under the primary category of data based on the feelings and opinions of the respondents. This research involves asking open-ended questions to a group of individuals usually ranging from 6-10 people, to provide feedback.

  • Information obtained is usually very detailed.
  • Cost-effective when compared to one-on-one interviews.
  • It reflects speed and efficiency in the supply of results.
  • Lacking depth in covering the nitty-gritty of a subject matter.
  • Bias might still be evident.
  • Requires interviewer training
  • The researcher has very little control over the outcome.
  • A few vocal voices can drown out the rest.
  • Difficulty in assembling an all-inclusive group.

What are the Best Data Collection Tools for Focus Groups?

A focus group is a data collection method that is tightly facilitated and structured around a set of questions. The purpose of the meeting is to extract from the participants’ detailed responses to these questions. The best tools for tackling Focus groups are: 

  • Two-Way – One group watches another group answer the questions posed by the moderator. After listening to what the other group has to offer, the group that listens is able to facilitate more discussion and could potentially draw different conclusions .
  • Dueling-Moderator – There are two moderators who play the devil’s advocate. The main positive of the dueling-moderator focus group is to facilitate new ideas by introducing new ways of thinking and varying viewpoints.
  • COMBINATION RESEARCH

This method of data collection encompasses the use of innovative methods to enhance participation in both individuals and groups. Also under the primary category, it is a combination of Interviews and Focus Groups while collecting qualitative data . This method is key when addressing sensitive subjects. 

  • Encourage participants to give responses.
  • It stimulates a deeper connection between participants.
  • The relative anonymity of respondents increases participation.
  • It improves the richness of the data collected.
  • It costs the most out of all the top 7.
  • It’s the most time-consuming.

What are the Best Data Collection Tools for Combination Research? 

The Combination Research method involves two or more data collection methods, for instance, interviews as well as questionnaires or a combination of semi-structured telephone interviews and focus groups. The best tools for combination research are: 

  • Online Survey –  The two tools combined here are online interviews and the use of questionnaires. This is a questionnaire that the target audience can complete over the Internet. It is timely, effective, and efficient. Especially since the data to be collected is quantitative in nature.
  • Dual-Moderator – The two tools combined here are focus groups and structured questionnaires. The structured questionnaires give a direction as to where the research is headed while two moderators take charge of the proceedings. Whilst one ensures the focus group session progresses smoothly, the other makes sure that the topics in question are all covered. Dual-moderator focus groups typically result in a more productive session and essentially lead to an optimum collection of data.

Why Formplus is the Best Data Collection Tool

  • Vast Options for Form Customization 

With Formplus, you can create your unique survey form. With options to change themes, font color, font, font type, layout, width, and more, you can create an attractive survey form. The builder also gives you as many features as possible to choose from and you do not need to be a graphic designer to create a form.

  • Extensive Analytics

Form Analytics, a feature in formplus helps you view the number of respondents, unique visits, total visits, abandonment rate, and average time spent before submission. This tool eliminates the need for a manual calculation of the received data and/or responses as well as the conversion rate for your poll.

  • Embed Survey Form on Your Website

Copy the link to your form and embed it as an iframe which will automatically load as your website loads, or as a popup that opens once the respondent clicks on the link. Embed the link on your Twitter page to give instant access to your followers.

research study data collection

  • Geolocation Support

The geolocation feature on Formplus lets you ascertain where individual responses are coming. It utilises Google Maps to pinpoint the longitude and latitude of the respondent, to the nearest accuracy, along with the responses.

  • Multi-Select feature

This feature helps to conserve horizontal space as it allows you to put multiple options in one field. This translates to including more information on the survey form. 

Read Also: 10 Reasons to Use Formplus for Online Data Collection

How to Use Formplus to collect online data in 7 simple steps. 

  • Register or sign up on Formplus builder : Start creating your preferred questionnaire or survey by signing up with either your Google, Facebook, or Email account.

research study data collection

Formplus gives you a free plan with basic features you can use to collect online data. Pricing plans with vast features starts at $20 monthly, with reasonable discounts for Education and Non-Profit Organizations. 

2. Input your survey title and use the form builder choice options to start creating your surveys. 

Use the choice option fields like single select, multiple select, checkbox, radio, and image choices to create your preferred multi-choice surveys online.

research study data collection

3. Do you want customers to rate any of your products or services delivery? 

Use the rating to allow survey respondents rate your products or services. This is an ideal quantitative research method of collecting data. 

research study data collection

4. Beautify your online questionnaire with Formplus Customisation features.

research study data collection

  • Change the theme color
  • Add your brand’s logo and image to the forms
  • Change the form width and layout
  • Edit the submission button if you want
  • Change text font color and sizes
  • Do you have already made custom CSS to beautify your questionnaire? If yes, just copy and paste it to the CSS option.

5. Edit your survey questionnaire settings for your specific needs

Choose where you choose to store your files and responses. Select a submission deadline, choose a timezone, limit respondents’ responses, enable Captcha to prevent spam, and collect location data of customers.

research study data collection

Set an introductory message to respondents before they begin the survey, toggle the “start button” post final submission message or redirect respondents to another page when they submit their questionnaires. 

Change the Email Notifications inventory and initiate an autoresponder message to all your survey questionnaire respondents. You can also transfer your forms to other users who can become form administrators.

6. Share links to your survey questionnaire page with customers.

There’s an option to copy and share the link as “Popup” or “Embed code” The data collection tool automatically creates a QR Code for Survey Questionnaire which you can download and share as appropriate. 

research study data collection

Congratulations if you’ve made it to this stage. You can start sharing the link to your survey questionnaire with your customers.

7. View your Responses to the Survey Questionnaire

Toggle with the presentation of your summary from the options. Whether as a single, table or cards.

research study data collection

8. Allow Formplus Analytics to interpret your Survey Questionnaire Data

research study data collection

  With online form builder analytics, a business can determine;

  • The number of times the survey questionnaire was filled
  • The number of customers reached
  • Abandonment Rate: The rate at which customers exit the form without submitting it.
  • Conversion Rate: The percentage of customers who completed the online form
  • Average time spent per visit
  • Location of customers/respondents.
  • The type of device used by the customer to complete the survey questionnaire.

7 Tips to Create The Best Surveys For Data Collections

  •  Define the goal of your survey – Once the goal of your survey is outlined, it will aid in deciding which questions are the top priority. A clear attainable goal would, for example, mirror a clear reason as to why something is happening. e.g. “The goal of this survey is to understand why Employees are leaving an establishment.”
  • Use close-ended clearly defined questions – Avoid open-ended questions and ensure you’re not suggesting your preferred answer to the respondent. If possible offer a range of answers with choice options and ratings.
  • Survey outlook should be attractive and Inviting – An attractive-looking survey encourages a higher number of recipients to respond to the survey. Check out Formplus Builder for colorful options to integrate into your survey design. You could use images and videos to keep participants glued to their screens.
  •   Assure Respondents about the safety of their data – You want your respondents to be assured whilst disclosing details of their personal information to you. It’s your duty to inform the respondents that the data they provide is confidential and only collected for the purpose of research.
  • Ensure your survey can be completed in record time – Ideally, in a typical survey, users should be able to respond in 100 seconds. It is pertinent to note that they, the respondents, are doing you a favor. Don’t stress them. Be brief and get straight to the point.
  • Do a trial survey – Preview your survey before sending out your surveys to the intended respondents. Make a trial version which you’ll send to a few individuals. Based on their responses, you can draw inferences and decide whether or not your survey is ready for the big time.
  • Attach a reward upon completion for users – Give your respondents something to look forward to at the end of the survey. Think of it as a penny for their troubles. It could well be the encouragement they need to not abandon the survey midway.

Try out Formplus today . You can start making your own surveys with the Formplus online survey builder. By applying these tips, you will definitely get the most out of your online surveys.

Top Survey Templates For Data Collection 

  • Customer Satisfaction Survey Template 

On the template, you can collect data to measure customer satisfaction over key areas like the commodity purchase and the level of service they received. It also gives insight as to which products the customer enjoyed, how often they buy such a product, and whether or not the customer is likely to recommend the product to a friend or acquaintance. 

  • Demographic Survey Template

With this template, you would be able to measure, with accuracy, the ratio of male to female, age range, and the number of unemployed persons in a particular country as well as obtain their personal details such as names and addresses.

Respondents are also able to state their religious and political views about the country under review.

  • Feedback Form Template

Contained in the template for the online feedback form is the details of a product and/or service used. Identifying this product or service and documenting how long the customer has used them.

The overall satisfaction is measured as well as the delivery of the services. The likelihood that the customer also recommends said product is also measured.

  • Online Questionnaire Template

The online questionnaire template houses the respondent’s data as well as educational qualifications to collect information to be used for academic research.

Respondents can also provide their gender, race, and field of study as well as present living conditions as prerequisite data for the research study.

  • Student Data Sheet Form Template 

The template is a data sheet containing all the relevant information of a student. The student’s name, home address, guardian’s name, record of attendance as well as performance in school is well represented on this template. This is a perfect data collection method to deploy for a school or an education organization.

Also included is a record for interaction with others as well as a space for a short comment on the overall performance and attitude of the student. 

  • Interview Consent Form Template

This online interview consent form template allows the interviewee to sign off their consent to use the interview data for research or report to journalists. With premium features like short text fields, upload, e-signature, etc., Formplus Builder is the perfect tool to create your preferred online consent forms without coding experience.

What is the Best Data Collection Method for Qualitative Data?

Answer: Combination Research

The best data collection method for a researcher for gathering qualitative data which generally is data relying on the feelings, opinions, and beliefs of the respondents would be Combination Research.

The reason why combination research is the best fit is that it encompasses the attributes of Interviews and Focus Groups. It is also useful when gathering data that is sensitive in nature. It can be described as an all-purpose quantitative data collection method.

Above all, combination research improves the richness of data collected when compared with other data collection methods for qualitative data.

research study data collection

What is the Best Data Collection Method for Quantitative Research Data?

Ans: Questionnaire

The best data collection method a researcher can employ in gathering quantitative data which takes into consideration data that can be represented in numbers and figures that can be deduced mathematically is the Questionnaire.

These can be administered to a large number of respondents while saving costs. For quantitative data that may be bulky or voluminous in nature, the use of a Questionnaire makes such data easy to visualize and analyze.

Another key advantage of the Questionnaire is that it can be used to compare and contrast previous research work done to measure changes.

Technology-Enabled Data Collection Methods

There are so many diverse methods available now in the world because technology has revolutionized the way data is being collected. It has provided efficient and innovative methods that anyone, especially researchers and organizations. Below are some technology-enabled data collection methods:

  • Online Surveys: Online surveys have gained popularity due to their ease of use and wide reach. You can distribute them through email, social media, or embed them on websites. Online surveys allow you to quickly complete data collection, automated data capture, and real-time analysis. Online surveys also offer features like skip logic, validation checks, and multimedia integration.
  • Mobile Surveys: With the widespread use of smartphones, mobile surveys’ popularity is also on the rise. Mobile surveys leverage the capabilities of mobile devices, and this allows respondents to participate at their convenience. This includes multimedia elements, location-based information, and real-time feedback. Mobile surveys are the best for capturing in-the-moment experiences or opinions.
  • Social Media Listening: Social media platforms are a good source of unstructured data that you can analyze to gain insights into customer sentiment and trends. Social media listening involves monitoring and analyzing social media conversations, mentions, and hashtags to understand public opinion, identify emerging topics, and assess brand reputation.
  • Wearable Devices and Sensors: You can embed wearable devices, such as fitness trackers or smartwatches, and sensors in everyday objects to capture continuous data on various physiological and environmental variables. This data can provide you with insights into health behaviors, activity patterns, sleep quality, and environmental conditions, among others.
  • Big Data Analytics: Big data analytics leverages large volumes of structured and unstructured data from various sources, such as transaction records, social media, and internet browsing. Advanced analytics techniques, like machine learning and natural language processing, can extract meaningful insights and patterns from this data, enabling organizations to make data-driven decisions.
Read Also: How Technology is Revolutionizing Data Collection

Faulty Data Collection Practices – Common Mistakes & Sources of Error

While technology-enabled data collection methods offer numerous advantages, there are some pitfalls and sources of error that you should be aware of. Here are some common mistakes and sources of error in data collection:

  • Population Specification Error: Population specification error occurs when the target population is not clearly defined or misidentified. This error leads to a mismatch between the research objectives and the actual population being studied, resulting in biased or inaccurate findings.
  • Sample Frame Error: Sample frame error occurs when the sampling frame, the list or source from which the sample is drawn, does not adequately represent the target population. This error can introduce selection bias and affect the generalizability of the findings.
  • Selection Error: Selection error occurs when the process of selecting participants or units for the study introduces bias. It can happen due to nonrandom sampling methods, inadequate sampling techniques, or self-selection bias. Selection error compromises the representativeness of the sample and affects the validity of the results.
  • Nonresponse Error: Nonresponse error occurs when selected participants choose not to participate or fail to respond to the data collection effort. Nonresponse bias can result in an unrepresentative sample if those who choose not to respond differ systematically from those who do respond. Efforts should be made to mitigate nonresponse and encourage participation to minimize this error.
  • Measurement Error: Measurement error arises from inaccuracies or inconsistencies in the measurement process. It can happen due to poorly designed survey instruments, ambiguous questions, respondent bias, or errors in data entry or coding. Measurement errors can lead to distorted or unreliable data, affecting the validity and reliability of the findings.

In order to mitigate these errors and ensure high-quality data collection, you should carefully plan your data collection procedures, and validate measurement tools. You should also use appropriate sampling techniques, employ randomization where possible, and minimize nonresponse through effective communication and incentives. Ensure you conduct regular checks and implement validation processes, and data cleaning procedures to identify and rectify errors during data analysis.

Best Practices for Data Collection

  • Clearly Define Objectives: Clearly define the research objectives and questions to guide the data collection process. This helps ensure that the collected data aligns with the research goals and provides relevant insights.
  • Plan Ahead: Develop a detailed data collection plan that includes the timeline, resources needed, and specific procedures to follow. This helps maintain consistency and efficiency throughout the data collection process.
  • Choose the Right Method: Select data collection methods that are appropriate for the research objectives and target population. Consider factors such as feasibility, cost-effectiveness, and the ability to capture the required data accurately.
  • Pilot Test : Before full-scale data collection, conduct a pilot test to identify any issues with the data collection instruments or procedures. This allows for refinement and improvement before data collection with the actual sample.
  • Train Data Collectors: If data collection involves human interaction, ensure that data collectors are properly trained on the data collection protocols, instruments, and ethical considerations. Consistent training helps minimize errors and maintain data quality.
  • Maintain Consistency: Follow standardized procedures throughout the data collection process to ensure consistency across data collectors and time. This includes using consistent measurement scales, instructions, and data recording methods.
  • Minimize Bias: Be aware of potential sources of bias in data collection and take steps to minimize their impact. Use randomization techniques, employ diverse data collectors, and implement strategies to mitigate response biases.
  • Ensure Data Quality: Implement quality control measures to ensure the accuracy, completeness, and reliability of the collected data. Conduct regular checks for data entry errors, inconsistencies, and missing values.
  • Maintain Data Confidentiality: Protect the privacy and confidentiality of participants’ data by implementing appropriate security measures. Ensure compliance with data protection regulations and obtain informed consent from participants.
  • Document the Process: Keep detailed documentation of the data collection process, including any deviations from the original plan, challenges encountered, and decisions made. This documentation facilitates transparency, replicability, and future analysis.

FAQs about Data Collection

  • What are secondary sources of data collection? Secondary sources of data collection are defined as the data that has been previously gathered and is available for your use as a researcher. These sources can include published research papers, government reports, statistical databases, and other existing datasets.
  • What are the primary sources of data collection? Primary sources of data collection involve collecting data directly from the original source also known as the firsthand sources. You can do this through surveys, interviews, observations, experiments, or other direct interactions with individuals or subjects of study.
  • How many types of data are there? There are two main types of data: qualitative and quantitative. Qualitative data is non-numeric and it includes information in the form of words, images, or descriptions. Quantitative data, on the other hand, is numeric and you can measure and analyze it statistically.
Sign up on Formplus Builder to create your preferred online surveys or questionnaire for data collection. You don’t need to be tech-savvy!

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Table of Contents

What is data collection, why do we need data collection, what are the different data collection methods, data collection tools, the importance of ensuring accurate and appropriate data collection, issues related to maintaining the integrity of data collection, what are common challenges in data collection, what are the key steps in the data collection process, data collection considerations and best practices, choose the right data science program, are you interested in a career in data science, what is data collection: methods, types, tools.

What is Data Collection? Definition, Types, Tools, and Techniques

The process of gathering and analyzing accurate data from various sources to find answers to research problems, trends and probabilities, etc., to evaluate possible outcomes is Known as Data Collection. Knowledge is power, information is knowledge, and data is information in digitized form, at least as defined in IT. Hence, data is power. But before you can leverage that data into a successful strategy for your organization or business, you need to gather it. That’s your first step.

So, to help you get the process started, we shine a spotlight on data collection. What exactly is it? Believe it or not, it’s more than just doing a Google search! Furthermore, what are the different types of data collection? And what kinds of data collection tools and data collection techniques exist?

If you want to get up to speed about what is data collection process, you’ve come to the right place. 

Transform raw data into captivating visuals with Simplilearn's hands-on Data Visualization Courses and captivate your audience. Also, master the art of data management with Simplilearn's comprehensive data management courses  - unlock new career opportunities today!

Data collection is the process of collecting and evaluating information or data from multiple sources to find answers to research problems, answer questions, evaluate outcomes, and forecast trends and probabilities. It is an essential phase in all types of research, analysis, and decision-making, including that done in the social sciences, business, and healthcare.

Accurate data collection is necessary to make informed business decisions, ensure quality assurance, and keep research integrity.

During data collection, the researchers must identify the data types, the sources of data, and what methods are being used. We will soon see that there are many different data collection methods . There is heavy reliance on data collection in research, commercial, and government fields.

Before an analyst begins collecting data, they must answer three questions first:

  • What’s the goal or purpose of this research?
  • What kinds of data are they planning on gathering?
  • What methods and procedures will be used to collect, store, and process the information?

Additionally, we can break up data into qualitative and quantitative types. Qualitative data covers descriptions such as color, size, quality, and appearance. Quantitative data, unsurprisingly, deals with numbers, such as statistics, poll numbers, percentages, etc.

Before a judge makes a ruling in a court case or a general creates a plan of attack, they must have as many relevant facts as possible. The best courses of action come from informed decisions, and information and data are synonymous.

The concept of data collection isn’t a new one, as we’ll see later, but the world has changed. There is far more data available today, and it exists in forms that were unheard of a century ago. The data collection process has had to change and grow with the times, keeping pace with technology.

Whether you’re in the world of academia, trying to conduct research, or part of the commercial sector, thinking of how to promote a new product, you need data collection to help you make better choices.

Now that you know what is data collection and why we need it, let's take a look at the different methods of data collection. While the phrase “data collection” may sound all high-tech and digital, it doesn’t necessarily entail things like computers, big data , and the internet. Data collection could mean a telephone survey, a mail-in comment card, or even some guy with a clipboard asking passersby some questions. But let’s see if we can sort the different data collection methods into a semblance of organized categories.

Primary and secondary methods of data collection are two approaches used to gather information for research or analysis purposes. Let's explore each data collection method in detail:

1. Primary Data Collection:

Primary data collection involves the collection of original data directly from the source or through direct interaction with the respondents. This method allows researchers to obtain firsthand information specifically tailored to their research objectives. There are various techniques for primary data collection, including:

a. Surveys and Questionnaires: Researchers design structured questionnaires or surveys to collect data from individuals or groups. These can be conducted through face-to-face interviews, telephone calls, mail, or online platforms.

b. Interviews: Interviews involve direct interaction between the researcher and the respondent. They can be conducted in person, over the phone, or through video conferencing. Interviews can be structured (with predefined questions), semi-structured (allowing flexibility), or unstructured (more conversational).

c. Observations: Researchers observe and record behaviors, actions, or events in their natural setting. This method is useful for gathering data on human behavior, interactions, or phenomena without direct intervention.

d. Experiments: Experimental studies involve the manipulation of variables to observe their impact on the outcome. Researchers control the conditions and collect data to draw conclusions about cause-and-effect relationships.

e. Focus Groups: Focus groups bring together a small group of individuals who discuss specific topics in a moderated setting. This method helps in understanding opinions, perceptions, and experiences shared by the participants.

2. Secondary Data Collection:

Secondary data collection involves using existing data collected by someone else for a purpose different from the original intent. Researchers analyze and interpret this data to extract relevant information. Secondary data can be obtained from various sources, including:

a. Published Sources: Researchers refer to books, academic journals, magazines, newspapers, government reports, and other published materials that contain relevant data.

b. Online Databases: Numerous online databases provide access to a wide range of secondary data, such as research articles, statistical information, economic data, and social surveys.

c. Government and Institutional Records: Government agencies, research institutions, and organizations often maintain databases or records that can be used for research purposes.

d. Publicly Available Data: Data shared by individuals, organizations, or communities on public platforms, websites, or social media can be accessed and utilized for research.

e. Past Research Studies: Previous research studies and their findings can serve as valuable secondary data sources. Researchers can review and analyze the data to gain insights or build upon existing knowledge.

Now that we’ve explained the various techniques, let’s narrow our focus even further by looking at some specific tools. For example, we mentioned interviews as a technique, but we can further break that down into different interview types (or “tools”).

Word Association

The researcher gives the respondent a set of words and asks them what comes to mind when they hear each word.

Sentence Completion

Researchers use sentence completion to understand what kind of ideas the respondent has. This tool involves giving an incomplete sentence and seeing how the interviewee finishes it.

Role-Playing

Respondents are presented with an imaginary situation and asked how they would act or react if it was real.

In-Person Surveys

The researcher asks questions in person.

Online/Web Surveys

These surveys are easy to accomplish, but some users may be unwilling to answer truthfully, if at all.

Mobile Surveys

These surveys take advantage of the increasing proliferation of mobile technology. Mobile collection surveys rely on mobile devices like tablets or smartphones to conduct surveys via SMS or mobile apps.

Phone Surveys

No researcher can call thousands of people at once, so they need a third party to handle the chore. However, many people have call screening and won’t answer.

Observation

Sometimes, the simplest method is the best. Researchers who make direct observations collect data quickly and easily, with little intrusion or third-party bias. Naturally, it’s only effective in small-scale situations.

Accurate data collecting is crucial to preserving the integrity of research, regardless of the subject of study or preferred method for defining data (quantitative, qualitative). Errors are less likely to occur when the right data gathering tools are used (whether they are brand-new ones, updated versions of them, or already available).

Among the effects of data collection done incorrectly, include the following -

  • Erroneous conclusions that squander resources
  • Decisions that compromise public policy
  • Incapacity to correctly respond to research inquiries
  • Bringing harm to participants who are humans or animals
  • Deceiving other researchers into pursuing futile research avenues
  • The study's inability to be replicated and validated

When these study findings are used to support recommendations for public policy, there is the potential to result in disproportionate harm, even if the degree of influence from flawed data collecting may vary by discipline and the type of investigation.

Let us now look at the various issues that we might face while maintaining the integrity of data collection.

In order to assist the errors detection process in the data gathering process, whether they were done purposefully (deliberate falsifications) or not, maintaining data integrity is the main justification (systematic or random errors).

Quality assurance and quality control are two strategies that help protect data integrity and guarantee the scientific validity of study results.

Each strategy is used at various stages of the research timeline:

  • Quality control - tasks that are performed both after and during data collecting
  • Quality assurance - events that happen before data gathering starts

Let us explore each of them in more detail now.

Quality Assurance

As data collecting comes before quality assurance, its primary goal is "prevention" (i.e., forestalling problems with data collection). The best way to protect the accuracy of data collection is through prevention. The uniformity of protocol created in the thorough and exhaustive procedures manual for data collecting serves as the best example of this proactive step. 

The likelihood of failing to spot issues and mistakes early in the research attempt increases when guides are written poorly. There are several ways to show these shortcomings:

  • Failure to determine the precise subjects and methods for retraining or training staff employees in data collecting
  • List of goods to be collected, in part
  • There isn't a system in place to track modifications to processes that may occur as the investigation continues.
  • Instead of detailed, step-by-step instructions on how to deliver tests, there is a vague description of the data gathering tools that will be employed.
  • Uncertainty regarding the date, procedure, and identity of the person or people in charge of examining the data
  • Incomprehensible guidelines for using, adjusting, and calibrating the data collection equipment.

Now, let us look at how to ensure Quality Control.

The Ultimate Ticket to Top Data Science Job Roles

The Ultimate Ticket to Top Data Science Job Roles

Quality Control

Despite the fact that quality control actions (detection/monitoring and intervention) take place both after and during data collection, the specifics should be meticulously detailed in the procedures manual. Establishing monitoring systems requires a specific communication structure, which is a prerequisite. Following the discovery of data collection problems, there should be no ambiguity regarding the information flow between the primary investigators and staff personnel. A poorly designed communication system promotes slack oversight and reduces opportunities for error detection.

Direct staff observation conference calls, during site visits, or frequent or routine assessments of data reports to spot discrepancies, excessive numbers, or invalid codes can all be used as forms of detection or monitoring. Site visits might not be appropriate for all disciplines. Still, without routine auditing of records, whether qualitative or quantitative, it will be challenging for investigators to confirm that data gathering is taking place in accordance with the manual's defined methods. Additionally, quality control determines the appropriate solutions, or "actions," to fix flawed data gathering procedures and reduce recurrences.

Problems with data collection, for instance, that call for immediate action include:

  • Fraud or misbehavior
  • Systematic mistakes, procedure violations 
  • Individual data items with errors
  • Issues with certain staff members or a site's performance 

Researchers are trained to include one or more secondary measures that can be used to verify the quality of information being obtained from the human subject in the social and behavioral sciences where primary data collection entails using human subjects. 

For instance, a researcher conducting a survey would be interested in learning more about the prevalence of risky behaviors among young adults as well as the social factors that influence these risky behaviors' propensity for and frequency. Let us now explore the common challenges with regard to data collection.

There are some prevalent challenges faced while collecting data, let us explore a few of them to understand them better and avoid them.

Data Quality Issues

The main threat to the broad and successful application of machine learning is poor data quality. Data quality must be your top priority if you want to make technologies like machine learning work for you. Let's talk about some of the most prevalent data quality problems in this blog article and how to fix them.

Inconsistent Data

When working with various data sources, it's conceivable that the same information will have discrepancies between sources. The differences could be in formats, units, or occasionally spellings. The introduction of inconsistent data might also occur during firm mergers or relocations. Inconsistencies in data have a tendency to accumulate and reduce the value of data if they are not continually resolved. Organizations that have heavily focused on data consistency do so because they only want reliable data to support their analytics.

Data Downtime

Data is the driving force behind the decisions and operations of data-driven businesses. However, there may be brief periods when their data is unreliable or not prepared. Customer complaints and subpar analytical outcomes are only two ways that this data unavailability can have a significant impact on businesses. A data engineer spends about 80% of their time updating, maintaining, and guaranteeing the integrity of the data pipeline. In order to ask the next business question, there is a high marginal cost due to the lengthy operational lead time from data capture to insight.

Schema modifications and migration problems are just two examples of the causes of data downtime. Data pipelines can be difficult due to their size and complexity. Data downtime must be continuously monitored, and it must be reduced through automation.

Ambiguous Data

Even with thorough oversight, some errors can still occur in massive databases or data lakes. For data streaming at a fast speed, the issue becomes more overwhelming. Spelling mistakes can go unnoticed, formatting difficulties can occur, and column heads might be deceptive. This unclear data might cause a number of problems for reporting and analytics.

Become a Data Scientist With Real-World Experience

Become a Data Scientist With Real-World Experience

Duplicate Data

Streaming data, local databases, and cloud data lakes are just a few of the sources of data that modern enterprises must contend with. They might also have application and system silos. These sources are likely to duplicate and overlap each other quite a bit. For instance, duplicate contact information has a substantial impact on customer experience. If certain prospects are ignored while others are engaged repeatedly, marketing campaigns suffer. The likelihood of biased analytical outcomes increases when duplicate data are present. It can also result in ML models with biased training data.

Too Much Data

While we emphasize data-driven analytics and its advantages, a data quality problem with excessive data exists. There is a risk of getting lost in an abundance of data when searching for information pertinent to your analytical efforts. Data scientists, data analysts, and business users devote 80% of their work to finding and organizing the appropriate data. With an increase in data volume, other problems with data quality become more serious, particularly when dealing with streaming data and big files or databases.

Inaccurate Data

For highly regulated businesses like healthcare, data accuracy is crucial. Given the current experience, it is more important than ever to increase the data quality for COVID-19 and later pandemics. Inaccurate information does not provide you with a true picture of the situation and cannot be used to plan the best course of action. Personalized customer experiences and marketing strategies underperform if your customer data is inaccurate.

Data inaccuracies can be attributed to a number of things, including data degradation, human mistake, and data drift. Worldwide data decay occurs at a rate of about 3% per month, which is quite concerning. Data integrity can be compromised while being transferred between different systems, and data quality might deteriorate with time.

Hidden Data

The majority of businesses only utilize a portion of their data, with the remainder sometimes being lost in data silos or discarded in data graveyards. For instance, the customer service team might not receive client data from sales, missing an opportunity to build more precise and comprehensive customer profiles. Missing out on possibilities to develop novel products, enhance services, and streamline procedures is caused by hidden data.

Finding Relevant Data

Finding relevant data is not so easy. There are several factors that we need to consider while trying to find relevant data, which include -

  • Relevant Domain
  • Relevant demographics
  • Relevant Time period and so many more factors that we need to consider while trying to find relevant data.

Data that is not relevant to our study in any of the factors render it obsolete and we cannot effectively proceed with its analysis. This could lead to incomplete research or analysis, re-collecting data again and again, or shutting down the study.

Deciding the Data to Collect

Determining what data to collect is one of the most important factors while collecting data and should be one of the first factors while collecting data. We must choose the subjects the data will cover, the sources we will be used to gather it, and the quantity of information we will require. Our responses to these queries will depend on our aims, or what we expect to achieve utilizing your data. As an illustration, we may choose to gather information on the categories of articles that website visitors between the ages of 20 and 50 most frequently access. We can also decide to compile data on the typical age of all the clients who made a purchase from your business over the previous month.

Not addressing this could lead to double work and collection of irrelevant data or ruining your study as a whole.

Dealing With Big Data

Big data refers to exceedingly massive data sets with more intricate and diversified structures. These traits typically result in increased challenges while storing, analyzing, and using additional methods of extracting results. Big data refers especially to data sets that are quite enormous or intricate that conventional data processing tools are insufficient. The overwhelming amount of data, both unstructured and structured, that a business faces on a daily basis. 

The amount of data produced by healthcare applications, the internet, social networking sites social, sensor networks, and many other businesses are rapidly growing as a result of recent technological advancements. Big data refers to the vast volume of data created from numerous sources in a variety of formats at extremely fast rates. Dealing with this kind of data is one of the many challenges of Data Collection and is a crucial step toward collecting effective data. 

Low Response and Other Research Issues

Poor design and low response rates were shown to be two issues with data collecting, particularly in health surveys that used questionnaires. This might lead to an insufficient or inadequate supply of data for the study. Creating an incentivized data collection program might be beneficial in this case to get more responses.

Now, let us look at the key steps in the data collection process.

In the Data Collection Process, there are 5 key steps. They are explained briefly below -

1. Decide What Data You Want to Gather

The first thing that we need to do is decide what information we want to gather. We must choose the subjects the data will cover, the sources we will use to gather it, and the quantity of information that we would require. For instance, we may choose to gather information on the categories of products that an average e-commerce website visitor between the ages of 30 and 45 most frequently searches for. 

2. Establish a Deadline for Data Collection

The process of creating a strategy for data collection can now begin. We should set a deadline for our data collection at the outset of our planning phase. Some forms of data we might want to continuously collect. We might want to build up a technique for tracking transactional data and website visitor statistics over the long term, for instance. However, we will track the data throughout a certain time frame if we are tracking it for a particular campaign. In these situations, we will have a schedule for when we will begin and finish gathering data. 

3. Select a Data Collection Approach

We will select the data collection technique that will serve as the foundation of our data gathering plan at this stage. We must take into account the type of information that we wish to gather, the time period during which we will receive it, and the other factors we decide on to choose the best gathering strategy.

4. Gather Information

Once our plan is complete, we can put our data collection plan into action and begin gathering data. In our DMP, we can store and arrange our data. We need to be careful to follow our plan and keep an eye on how it's doing. Especially if we are collecting data regularly, setting up a timetable for when we will be checking in on how our data gathering is going may be helpful. As circumstances alter and we learn new details, we might need to amend our plan.

5. Examine the Information and Apply Your Findings

It's time to examine our data and arrange our findings after we have gathered all of our information. The analysis stage is essential because it transforms unprocessed data into insightful knowledge that can be applied to better our marketing plans, goods, and business judgments. The analytics tools included in our DMP can be used to assist with this phase. We can put the discoveries to use to enhance our business once we have discovered the patterns and insights in our data.

Let us now look at some data collection considerations and best practices that one might follow.

We must carefully plan before spending time and money traveling to the field to gather data. While saving time and resources, effective data collection strategies can help us collect richer, more accurate, and richer data.

Below, we will be discussing some of the best practices that we can follow for the best results -

1. Take Into Account the Price of Each Extra Data Point

Once we have decided on the data we want to gather, we need to make sure to take the expense of doing so into account. Our surveyors and respondents will incur additional costs for each additional data point or survey question.

2. Plan How to Gather Each Data Piece

There is a dearth of freely accessible data. Sometimes the data is there, but we may not have access to it. For instance, unless we have a compelling cause, we cannot openly view another person's medical information. It could be challenging to measure several types of information.

Consider how time-consuming and difficult it will be to gather each piece of information while deciding what data to acquire.

3. Think About Your Choices for Data Collecting Using Mobile Devices

Mobile-based data collecting can be divided into three categories -

  • IVRS (interactive voice response technology) -  Will call the respondents and ask them questions that have already been recorded. 
  • SMS data collection - Will send a text message to the respondent, who can then respond to questions by text on their phone. 
  • Field surveyors - Can directly enter data into an interactive questionnaire while speaking to each respondent, thanks to smartphone apps.

We need to make sure to select the appropriate tool for our survey and responders because each one has its own disadvantages and advantages.

4. Carefully Consider the Data You Need to Gather

It's all too easy to get information about anything and everything, but it's crucial to only gather the information that we require. 

It is helpful to consider these 3 questions:

  • What details will be helpful?
  • What details are available?
  • What specific details do you require?

5. Remember to Consider Identifiers

Identifiers, or details describing the context and source of a survey response, are just as crucial as the information about the subject or program that we are actually researching.

In general, adding more identifiers will enable us to pinpoint our program's successes and failures with greater accuracy, but moderation is the key.

6. Data Collecting Through Mobile Devices is the Way to Go

Although collecting data on paper is still common, modern technology relies heavily on mobile devices. They enable us to gather many various types of data at relatively lower prices and are accurate as well as quick. There aren't many reasons not to pick mobile-based data collecting with the boom of low-cost Android devices that are available nowadays.

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1. What is data collection with example?

Data collection is the process of collecting and analyzing information on relevant variables in a predetermined, methodical way so that one can respond to specific research questions, test hypotheses, and assess results. Data collection can be either qualitative or quantitative. Example: A company collects customer feedback through online surveys and social media monitoring to improve their products and services.

2. What are the primary data collection methods?

As is well known, gathering primary data is costly and time intensive. The main techniques for gathering data are observation, interviews, questionnaires, schedules, and surveys.

3. What are data collection tools?

The term "data collecting tools" refers to the tools/devices used to gather data, such as a paper questionnaire or a system for computer-assisted interviews. Tools used to gather data include case studies, checklists, interviews, occasionally observation, surveys, and questionnaires.

4. What’s the difference between quantitative and qualitative methods?

While qualitative research focuses on words and meanings, quantitative research deals with figures and statistics. You can systematically measure variables and test hypotheses using quantitative methods. You can delve deeper into ideas and experiences using qualitative methodologies.

5. What are quantitative data collection methods?

While there are numerous other ways to get quantitative information, the methods indicated above—probability sampling, interviews, questionnaire observation, and document review—are the most typical and frequently employed, whether collecting information offline or online.

6. What is mixed methods research?

User research that includes both qualitative and quantitative techniques is known as mixed methods research. For deeper user insights, mixed methods research combines insightful user data with useful statistics.

7. What are the benefits of collecting data?

Collecting data offers several benefits, including:

  • Knowledge and Insight
  • Evidence-Based Decision Making
  • Problem Identification and Solution
  • Validation and Evaluation
  • Identifying Trends and Predictions
  • Support for Research and Development
  • Policy Development
  • Quality Improvement
  • Personalization and Targeting
  • Knowledge Sharing and Collaboration

8. What’s the difference between reliability and validity?

Reliability is about consistency and stability, while validity is about accuracy and appropriateness. Reliability focuses on the consistency of results, while validity focuses on whether the results are actually measuring what they are intended to measure. Both reliability and validity are crucial considerations in research to ensure the trustworthiness and meaningfulness of the collected data and measurements.

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  • Knowledge Base

Methodology

  • What Is a Research Design | Types, Guide & Examples

What Is a Research Design | Types, Guide & Examples

Published on June 7, 2021 by Shona McCombes . Revised on November 20, 2023 by Pritha Bhandari.

A research design is a strategy for answering your   research question  using empirical data. Creating a research design means making decisions about:

  • Your overall research objectives and approach
  • Whether you’ll rely on primary research or secondary research
  • Your sampling methods or criteria for selecting subjects
  • Your data collection methods
  • The procedures you’ll follow to collect data
  • Your data analysis methods

A well-planned research design helps ensure that your methods match your research objectives and that you use the right kind of analysis for your data.

Table of contents

Step 1: consider your aims and approach, step 2: choose a type of research design, step 3: identify your population and sampling method, step 4: choose your data collection methods, step 5: plan your data collection procedures, step 6: decide on your data analysis strategies, other interesting articles, frequently asked questions about research design.

  • Introduction

Before you can start designing your research, you should already have a clear idea of the research question you want to investigate.

There are many different ways you could go about answering this question. Your research design choices should be driven by your aims and priorities—start by thinking carefully about what you want to achieve.

The first choice you need to make is whether you’ll take a qualitative or quantitative approach.

Qualitative approach Quantitative approach
and describe frequencies, averages, and correlations about relationships between variables

Qualitative research designs tend to be more flexible and inductive , allowing you to adjust your approach based on what you find throughout the research process.

Quantitative research designs tend to be more fixed and deductive , with variables and hypotheses clearly defined in advance of data collection.

It’s also possible to use a mixed-methods design that integrates aspects of both approaches. By combining qualitative and quantitative insights, you can gain a more complete picture of the problem you’re studying and strengthen the credibility of your conclusions.

Practical and ethical considerations when designing research

As well as scientific considerations, you need to think practically when designing your research. If your research involves people or animals, you also need to consider research ethics .

  • How much time do you have to collect data and write up the research?
  • Will you be able to gain access to the data you need (e.g., by travelling to a specific location or contacting specific people)?
  • Do you have the necessary research skills (e.g., statistical analysis or interview techniques)?
  • Will you need ethical approval ?

At each stage of the research design process, make sure that your choices are practically feasible.

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Within both qualitative and quantitative approaches, there are several types of research design to choose from. Each type provides a framework for the overall shape of your research.

Types of quantitative research designs

Quantitative designs can be split into four main types.

  • Experimental and   quasi-experimental designs allow you to test cause-and-effect relationships
  • Descriptive and correlational designs allow you to measure variables and describe relationships between them.
Type of design Purpose and characteristics
Experimental relationships effect on a
Quasi-experimental )
Correlational
Descriptive

With descriptive and correlational designs, you can get a clear picture of characteristics, trends and relationships as they exist in the real world. However, you can’t draw conclusions about cause and effect (because correlation doesn’t imply causation ).

Experiments are the strongest way to test cause-and-effect relationships without the risk of other variables influencing the results. However, their controlled conditions may not always reflect how things work in the real world. They’re often also more difficult and expensive to implement.

Types of qualitative research designs

Qualitative designs are less strictly defined. This approach is about gaining a rich, detailed understanding of a specific context or phenomenon, and you can often be more creative and flexible in designing your research.

The table below shows some common types of qualitative design. They often have similar approaches in terms of data collection, but focus on different aspects when analyzing the data.

Type of design Purpose and characteristics
Grounded theory
Phenomenology

Your research design should clearly define who or what your research will focus on, and how you’ll go about choosing your participants or subjects.

In research, a population is the entire group that you want to draw conclusions about, while a sample is the smaller group of individuals you’ll actually collect data from.

Defining the population

A population can be made up of anything you want to study—plants, animals, organizations, texts, countries, etc. In the social sciences, it most often refers to a group of people.

For example, will you focus on people from a specific demographic, region or background? Are you interested in people with a certain job or medical condition, or users of a particular product?

The more precisely you define your population, the easier it will be to gather a representative sample.

  • Sampling methods

Even with a narrowly defined population, it’s rarely possible to collect data from every individual. Instead, you’ll collect data from a sample.

To select a sample, there are two main approaches: probability sampling and non-probability sampling . The sampling method you use affects how confidently you can generalize your results to the population as a whole.

Probability sampling Non-probability sampling

Probability sampling is the most statistically valid option, but it’s often difficult to achieve unless you’re dealing with a very small and accessible population.

For practical reasons, many studies use non-probability sampling, but it’s important to be aware of the limitations and carefully consider potential biases. You should always make an effort to gather a sample that’s as representative as possible of the population.

Case selection in qualitative research

In some types of qualitative designs, sampling may not be relevant.

For example, in an ethnography or a case study , your aim is to deeply understand a specific context, not to generalize to a population. Instead of sampling, you may simply aim to collect as much data as possible about the context you are studying.

In these types of design, you still have to carefully consider your choice of case or community. You should have a clear rationale for why this particular case is suitable for answering your research question .

For example, you might choose a case study that reveals an unusual or neglected aspect of your research problem, or you might choose several very similar or very different cases in order to compare them.

Data collection methods are ways of directly measuring variables and gathering information. They allow you to gain first-hand knowledge and original insights into your research problem.

You can choose just one data collection method, or use several methods in the same study.

Survey methods

Surveys allow you to collect data about opinions, behaviors, experiences, and characteristics by asking people directly. There are two main survey methods to choose from: questionnaires and interviews .

Questionnaires Interviews
)

Observation methods

Observational studies allow you to collect data unobtrusively, observing characteristics, behaviors or social interactions without relying on self-reporting.

Observations may be conducted in real time, taking notes as you observe, or you might make audiovisual recordings for later analysis. They can be qualitative or quantitative.

Quantitative observation

Other methods of data collection

There are many other ways you might collect data depending on your field and topic.

Field Examples of data collection methods
Media & communication Collecting a sample of texts (e.g., speeches, articles, or social media posts) for data on cultural norms and narratives
Psychology Using technologies like neuroimaging, eye-tracking, or computer-based tasks to collect data on things like attention, emotional response, or reaction time
Education Using tests or assignments to collect data on knowledge and skills
Physical sciences Using scientific instruments to collect data on things like weight, blood pressure, or chemical composition

If you’re not sure which methods will work best for your research design, try reading some papers in your field to see what kinds of data collection methods they used.

Secondary data

If you don’t have the time or resources to collect data from the population you’re interested in, you can also choose to use secondary data that other researchers already collected—for example, datasets from government surveys or previous studies on your topic.

With this raw data, you can do your own analysis to answer new research questions that weren’t addressed by the original study.

Using secondary data can expand the scope of your research, as you may be able to access much larger and more varied samples than you could collect yourself.

However, it also means you don’t have any control over which variables to measure or how to measure them, so the conclusions you can draw may be limited.

As well as deciding on your methods, you need to plan exactly how you’ll use these methods to collect data that’s consistent, accurate, and unbiased.

Planning systematic procedures is especially important in quantitative research, where you need to precisely define your variables and ensure your measurements are high in reliability and validity.

Operationalization

Some variables, like height or age, are easily measured. But often you’ll be dealing with more abstract concepts, like satisfaction, anxiety, or competence. Operationalization means turning these fuzzy ideas into measurable indicators.

If you’re using observations , which events or actions will you count?

If you’re using surveys , which questions will you ask and what range of responses will be offered?

You may also choose to use or adapt existing materials designed to measure the concept you’re interested in—for example, questionnaires or inventories whose reliability and validity has already been established.

Reliability and validity

Reliability means your results can be consistently reproduced, while validity means that you’re actually measuring the concept you’re interested in.

Reliability Validity
) )

For valid and reliable results, your measurement materials should be thoroughly researched and carefully designed. Plan your procedures to make sure you carry out the same steps in the same way for each participant.

If you’re developing a new questionnaire or other instrument to measure a specific concept, running a pilot study allows you to check its validity and reliability in advance.

Sampling procedures

As well as choosing an appropriate sampling method , you need a concrete plan for how you’ll actually contact and recruit your selected sample.

That means making decisions about things like:

  • How many participants do you need for an adequate sample size?
  • What inclusion and exclusion criteria will you use to identify eligible participants?
  • How will you contact your sample—by mail, online, by phone, or in person?

If you’re using a probability sampling method , it’s important that everyone who is randomly selected actually participates in the study. How will you ensure a high response rate?

If you’re using a non-probability method , how will you avoid research bias and ensure a representative sample?

Data management

It’s also important to create a data management plan for organizing and storing your data.

Will you need to transcribe interviews or perform data entry for observations? You should anonymize and safeguard any sensitive data, and make sure it’s backed up regularly.

Keeping your data well-organized will save time when it comes to analyzing it. It can also help other researchers validate and add to your findings (high replicability ).

On its own, raw data can’t answer your research question. The last step of designing your research is planning how you’ll analyze the data.

Quantitative data analysis

In quantitative research, you’ll most likely use some form of statistical analysis . With statistics, you can summarize your sample data, make estimates, and test hypotheses.

Using descriptive statistics , you can summarize your sample data in terms of:

  • The distribution of the data (e.g., the frequency of each score on a test)
  • The central tendency of the data (e.g., the mean to describe the average score)
  • The variability of the data (e.g., the standard deviation to describe how spread out the scores are)

The specific calculations you can do depend on the level of measurement of your variables.

Using inferential statistics , you can:

  • Make estimates about the population based on your sample data.
  • Test hypotheses about a relationship between variables.

Regression and correlation tests look for associations between two or more variables, while comparison tests (such as t tests and ANOVAs ) look for differences in the outcomes of different groups.

Your choice of statistical test depends on various aspects of your research design, including the types of variables you’re dealing with and the distribution of your data.

Qualitative data analysis

In qualitative research, your data will usually be very dense with information and ideas. Instead of summing it up in numbers, you’ll need to comb through the data in detail, interpret its meanings, identify patterns, and extract the parts that are most relevant to your research question.

Two of the most common approaches to doing this are thematic analysis and discourse analysis .

Approach Characteristics
Thematic analysis
Discourse analysis

There are many other ways of analyzing qualitative data depending on the aims of your research. To get a sense of potential approaches, try reading some qualitative research papers in your field.

If you want to know more about the research process , methodology , research bias , or statistics , make sure to check out some of our other articles with explanations and examples.

  • Simple random sampling
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  • Cluster sampling
  • Likert scales
  • Reproducibility

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  • Null hypothesis
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  • Implicit bias
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A research design is a strategy for answering your   research question . It defines your overall approach and determines how you will collect and analyze data.

A well-planned research design helps ensure that your methods match your research aims, that you collect high-quality data, and that you use the right kind of analysis to answer your questions, utilizing credible sources . This allows you to draw valid , trustworthy conclusions.

Quantitative research designs can be divided into two main categories:

  • Correlational and descriptive designs are used to investigate characteristics, averages, trends, and associations between variables.
  • Experimental and quasi-experimental designs are used to test causal relationships .

Qualitative research designs tend to be more flexible. Common types of qualitative design include case study , ethnography , and grounded theory designs.

The priorities of a research design can vary depending on the field, but you usually have to specify:

  • Your research questions and/or hypotheses
  • Your overall approach (e.g., qualitative or quantitative )
  • The type of design you’re using (e.g., a survey , experiment , or case study )
  • Your data collection methods (e.g., questionnaires , observations)
  • Your data collection procedures (e.g., operationalization , timing and data management)
  • Your data analysis methods (e.g., statistical tests  or thematic analysis )

A sample is a subset of individuals from a larger population . Sampling means selecting the group that you will actually collect data from in your research. For example, if you are researching the opinions of students in your university, you could survey a sample of 100 students.

In statistics, sampling allows you to test a hypothesis about the characteristics of a population.

Operationalization means turning abstract conceptual ideas into measurable observations.

For example, the concept of social anxiety isn’t directly observable, but it can be operationally defined in terms of self-rating scores, behavioral avoidance of crowded places, or physical anxiety symptoms in social situations.

Before collecting data , it’s important to consider how you will operationalize the variables that you want to measure.

A research project is an academic, scientific, or professional undertaking to answer a research question . Research projects can take many forms, such as qualitative or quantitative , descriptive , longitudinal , experimental , or correlational . What kind of research approach you choose will depend on your topic.

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Research Design, Data Collection, and Analysis Plan: Version 1.1: The Family Options 12-Year Study

Report Acceptance Date: April 2024 (80 pages)

Posted Date: June 28, 2024

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HUD’s Evaluation Policy states, under the principle of transparency, that “If the findings of a HUD evaluation will have broad public interest and includes a counterfactual, PD&R will publish a synopsis of the research design, data collection and analysis plan soon after it is approved…” The enclosed RD/DCAP outlines the approach that the research team from Abt Associates will take in carrying out the Family Options 12 Year Study . This final RD/DCAP has been approved by the Contracting Officer’s Representative for this research effort after review and comment from multiple HUD program offices.

HUD launched the Family Options Study in 2010 as a multi-site experiment designed to develop evidence about which types of housing and services interventions work best for families who experience homelessness. Reports documenting the impact analyses in the short-term (2015) and the longer term (2016) found that priority access to a long-term rent subsidy such as a Housing Choice Voucher produced substantial benefits for families who had experienced homelessness . Based on these findings, HUD is attempting to administer a 12-year followup survey to the original sample of families that enrolled in the study over a decade ago. The RD/DCAP outlines the key research questions, the confirmatory and exploratory outcomes to be measured, the data sources to be collected or accessed, and the analytic approach to be undertaken.

HUD is publishing this date-stamped RD/DCAP on www.huduser.gov as a form of preregistration, which is a proactive step that can be taken for HUD’s experimental studies in response to concerns about the potential for researchers to manipulate data and analysis methods to support pre-determined or desired conclusions.

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Markets for Diversifying Agriculture: Case Studies of the U.S Midwest

Agricultural diversification stands out as a critical strategy for addressing challenges and seizing opportunities within the agricultural landscape, especially in regions like the Midwest of the U.S. This research delves into the dynamics, opportunities, challenges, and key success drivers associated with agricultural diversification in the Midwest, focusing on three primary crops: oats, peas, and wheat. Employing a case study methodology grounded in empirical and contextual inquiry principles, the research aims to grasp the nuances of diversified agriculture. Data collection integrates primary and secondary sources, including semi-structured interviews and participation in field days. The data collection period spanned from October 2022 to February 2024. Interviews with 29 stakeholders, including farmers, industry representatives, agricultural cooperatives, and non-profits, provided insights into diversified agriculture practices.

Each case study provides in-depth insights into the opportunities, challenges, and key drivers of success associated with promoting diversified agriculture initiatives. These case studies underscore the significance of innovation, market access, sustainability, and collaboration in driving success within the industry. The cross-case analysis offers a comprehensive examination of the potential for agricultural diversification in the US Midwest. Through a comparative analysis of the three case studies, commonalities and key themes emerge, shedding light on stakeholder dynamics, business strategies, operational aspects, and scalability factors.

In summary, this research significantly contributes to the body of knowledge on agricultural diversification, offering insights that can guide future decisions, agricultural practices, and research endeavors aimed at promoting sustainability and resilience in the agricultural sector in the US Midwest.

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Qualitative Research: Data Collection, Analysis, and Management

Introduction.

In an earlier paper, 1 we presented an introduction to using qualitative research methods in pharmacy practice. In this article, we review some principles of the collection, analysis, and management of qualitative data to help pharmacists interested in doing research in their practice to continue their learning in this area. Qualitative research can help researchers to access the thoughts and feelings of research participants, which can enable development of an understanding of the meaning that people ascribe to their experiences. Whereas quantitative research methods can be used to determine how many people undertake particular behaviours, qualitative methods can help researchers to understand how and why such behaviours take place. Within the context of pharmacy practice research, qualitative approaches have been used to examine a diverse array of topics, including the perceptions of key stakeholders regarding prescribing by pharmacists and the postgraduation employment experiences of young pharmacists (see “Further Reading” section at the end of this article).

In the previous paper, 1 we outlined 3 commonly used methodologies: ethnography 2 , grounded theory 3 , and phenomenology. 4 Briefly, ethnography involves researchers using direct observation to study participants in their “real life” environment, sometimes over extended periods. Grounded theory and its later modified versions (e.g., Strauss and Corbin 5 ) use face-to-face interviews and interactions such as focus groups to explore a particular research phenomenon and may help in clarifying a less-well-understood problem, situation, or context. Phenomenology shares some features with grounded theory (such as an exploration of participants’ behaviour) and uses similar techniques to collect data, but it focuses on understanding how human beings experience their world. It gives researchers the opportunity to put themselves in another person’s shoes and to understand the subjective experiences of participants. 6 Some researchers use qualitative methodologies but adopt a different standpoint, and an example of this appears in the work of Thurston and others, 7 discussed later in this paper.

Qualitative work requires reflection on the part of researchers, both before and during the research process, as a way of providing context and understanding for readers. When being reflexive, researchers should not try to simply ignore or avoid their own biases (as this would likely be impossible); instead, reflexivity requires researchers to reflect upon and clearly articulate their position and subjectivities (world view, perspectives, biases), so that readers can better understand the filters through which questions were asked, data were gathered and analyzed, and findings were reported. From this perspective, bias and subjectivity are not inherently negative but they are unavoidable; as a result, it is best that they be articulated up-front in a manner that is clear and coherent for readers.

THE PARTICIPANT’S VIEWPOINT

What qualitative study seeks to convey is why people have thoughts and feelings that might affect the way they behave. Such study may occur in any number of contexts, but here, we focus on pharmacy practice and the way people behave with regard to medicines use (e.g., to understand patients’ reasons for nonadherence with medication therapy or to explore physicians’ resistance to pharmacists’ clinical suggestions). As we suggested in our earlier article, 1 an important point about qualitative research is that there is no attempt to generalize the findings to a wider population. Qualitative research is used to gain insights into people’s feelings and thoughts, which may provide the basis for a future stand-alone qualitative study or may help researchers to map out survey instruments for use in a quantitative study. It is also possible to use different types of research in the same study, an approach known as “mixed methods” research, and further reading on this topic may be found at the end of this paper.

The role of the researcher in qualitative research is to attempt to access the thoughts and feelings of study participants. This is not an easy task, as it involves asking people to talk about things that may be very personal to them. Sometimes the experiences being explored are fresh in the participant’s mind, whereas on other occasions reliving past experiences may be difficult. However the data are being collected, a primary responsibility of the researcher is to safeguard participants and their data. Mechanisms for such safeguarding must be clearly articulated to participants and must be approved by a relevant research ethics review board before the research begins. Researchers and practitioners new to qualitative research should seek advice from an experienced qualitative researcher before embarking on their project.

DATA COLLECTION

Whatever philosophical standpoint the researcher is taking and whatever the data collection method (e.g., focus group, one-to-one interviews), the process will involve the generation of large amounts of data. In addition to the variety of study methodologies available, there are also different ways of making a record of what is said and done during an interview or focus group, such as taking handwritten notes or video-recording. If the researcher is audio- or video-recording data collection, then the recordings must be transcribed verbatim before data analysis can begin. As a rough guide, it can take an experienced researcher/transcriber 8 hours to transcribe one 45-minute audio-recorded interview, a process than will generate 20–30 pages of written dialogue.

Many researchers will also maintain a folder of “field notes” to complement audio-taped interviews. Field notes allow the researcher to maintain and comment upon impressions, environmental contexts, behaviours, and nonverbal cues that may not be adequately captured through the audio-recording; they are typically handwritten in a small notebook at the same time the interview takes place. Field notes can provide important context to the interpretation of audio-taped data and can help remind the researcher of situational factors that may be important during data analysis. Such notes need not be formal, but they should be maintained and secured in a similar manner to audio tapes and transcripts, as they contain sensitive information and are relevant to the research. For more information about collecting qualitative data, please see the “Further Reading” section at the end of this paper.

DATA ANALYSIS AND MANAGEMENT

If, as suggested earlier, doing qualitative research is about putting oneself in another person’s shoes and seeing the world from that person’s perspective, the most important part of data analysis and management is to be true to the participants. It is their voices that the researcher is trying to hear, so that they can be interpreted and reported on for others to read and learn from. To illustrate this point, consider the anonymized transcript excerpt presented in Appendix 1 , which is taken from a research interview conducted by one of the authors (J.S.). We refer to this excerpt throughout the remainder of this paper to illustrate how data can be managed, analyzed, and presented.

Interpretation of Data

Interpretation of the data will depend on the theoretical standpoint taken by researchers. For example, the title of the research report by Thurston and others, 7 “Discordant indigenous and provider frames explain challenges in improving access to arthritis care: a qualitative study using constructivist grounded theory,” indicates at least 2 theoretical standpoints. The first is the culture of the indigenous population of Canada and the place of this population in society, and the second is the social constructivist theory used in the constructivist grounded theory method. With regard to the first standpoint, it can be surmised that, to have decided to conduct the research, the researchers must have felt that there was anecdotal evidence of differences in access to arthritis care for patients from indigenous and non-indigenous backgrounds. With regard to the second standpoint, it can be surmised that the researchers used social constructivist theory because it assumes that behaviour is socially constructed; in other words, people do things because of the expectations of those in their personal world or in the wider society in which they live. (Please see the “Further Reading” section for resources providing more information about social constructivist theory and reflexivity.) Thus, these 2 standpoints (and there may have been others relevant to the research of Thurston and others 7 ) will have affected the way in which these researchers interpreted the experiences of the indigenous population participants and those providing their care. Another standpoint is feminist standpoint theory which, among other things, focuses on marginalized groups in society. Such theories are helpful to researchers, as they enable us to think about things from a different perspective. Being aware of the standpoints you are taking in your own research is one of the foundations of qualitative work. Without such awareness, it is easy to slip into interpreting other people’s narratives from your own viewpoint, rather than that of the participants.

To analyze the example in Appendix 1 , we will adopt a phenomenological approach because we want to understand how the participant experienced the illness and we want to try to see the experience from that person’s perspective. It is important for the researcher to reflect upon and articulate his or her starting point for such analysis; for example, in the example, the coder could reflect upon her own experience as a female of a majority ethnocultural group who has lived within middle class and upper middle class settings. This personal history therefore forms the filter through which the data will be examined. This filter does not diminish the quality or significance of the analysis, since every researcher has his or her own filters; however, by explicitly stating and acknowledging what these filters are, the researcher makes it easer for readers to contextualize the work.

Transcribing and Checking

For the purposes of this paper it is assumed that interviews or focus groups have been audio-recorded. As mentioned above, transcribing is an arduous process, even for the most experienced transcribers, but it must be done to convert the spoken word to the written word to facilitate analysis. For anyone new to conducting qualitative research, it is beneficial to transcribe at least one interview and one focus group. It is only by doing this that researchers realize how difficult the task is, and this realization affects their expectations when asking others to transcribe. If the research project has sufficient funding, then a professional transcriber can be hired to do the work. If this is the case, then it is a good idea to sit down with the transcriber, if possible, and talk through the research and what the participants were talking about. This background knowledge for the transcriber is especially important in research in which people are using jargon or medical terms (as in pharmacy practice). Involving your transcriber in this way makes the work both easier and more rewarding, as he or she will feel part of the team. Transcription editing software is also available, but it is expensive. For example, ELAN (more formally known as EUDICO Linguistic Annotator, developed at the Technical University of Berlin) 8 is a tool that can help keep data organized by linking media and data files (particularly valuable if, for example, video-taping of interviews is complemented by transcriptions). It can also be helpful in searching complex data sets. Products such as ELAN do not actually automatically transcribe interviews or complete analyses, and they do require some time and effort to learn; nonetheless, for some research applications, it may be a valuable to consider such software tools.

All audio recordings should be transcribed verbatim, regardless of how intelligible the transcript may be when it is read back. Lines of text should be numbered. Once the transcription is complete, the researcher should read it while listening to the recording and do the following: correct any spelling or other errors; anonymize the transcript so that the participant cannot be identified from anything that is said (e.g., names, places, significant events); insert notations for pauses, laughter, looks of discomfort; insert any punctuation, such as commas and full stops (periods) (see Appendix 1 for examples of inserted punctuation), and include any other contextual information that might have affected the participant (e.g., temperature or comfort of the room).

Dealing with the transcription of a focus group is slightly more difficult, as multiple voices are involved. One way of transcribing such data is to “tag” each voice (e.g., Voice A, Voice B). In addition, the focus group will usually have 2 facilitators, whose respective roles will help in making sense of the data. While one facilitator guides participants through the topic, the other can make notes about context and group dynamics. More information about group dynamics and focus groups can be found in resources listed in the “Further Reading” section.

Reading between the Lines

During the process outlined above, the researcher can begin to get a feel for the participant’s experience of the phenomenon in question and can start to think about things that could be pursued in subsequent interviews or focus groups (if appropriate). In this way, one participant’s narrative informs the next, and the researcher can continue to interview until nothing new is being heard or, as it says in the text books, “saturation is reached”. While continuing with the processes of coding and theming (described in the next 2 sections), it is important to consider not just what the person is saying but also what they are not saying. For example, is a lengthy pause an indication that the participant is finding the subject difficult, or is the person simply deciding what to say? The aim of the whole process from data collection to presentation is to tell the participants’ stories using exemplars from their own narratives, thus grounding the research findings in the participants’ lived experiences.

Smith 9 suggested a qualitative research method known as interpretative phenomenological analysis, which has 2 basic tenets: first, that it is rooted in phenomenology, attempting to understand the meaning that individuals ascribe to their lived experiences, and second, that the researcher must attempt to interpret this meaning in the context of the research. That the researcher has some knowledge and expertise in the subject of the research means that he or she can have considerable scope in interpreting the participant’s experiences. Larkin and others 10 discussed the importance of not just providing a description of what participants say. Rather, interpretative phenomenological analysis is about getting underneath what a person is saying to try to truly understand the world from his or her perspective.

Once all of the research interviews have been transcribed and checked, it is time to begin coding. Field notes compiled during an interview can be a useful complementary source of information to facilitate this process, as the gap in time between an interview, transcribing, and coding can result in memory bias regarding nonverbal or environmental context issues that may affect interpretation of data.

Coding refers to the identification of topics, issues, similarities, and differences that are revealed through the participants’ narratives and interpreted by the researcher. This process enables the researcher to begin to understand the world from each participant’s perspective. Coding can be done by hand on a hard copy of the transcript, by making notes in the margin or by highlighting and naming sections of text. More commonly, researchers use qualitative research software (e.g., NVivo, QSR International Pty Ltd; www.qsrinternational.com/products_nvivo.aspx ) to help manage their transcriptions. It is advised that researchers undertake a formal course in the use of such software or seek supervision from a researcher experienced in these tools.

Returning to Appendix 1 and reading from lines 8–11, a code for this section might be “diagnosis of mental health condition”, but this would just be a description of what the participant is talking about at that point. If we read a little more deeply, we can ask ourselves how the participant might have come to feel that the doctor assumed he or she was aware of the diagnosis or indeed that they had only just been told the diagnosis. There are a number of pauses in the narrative that might suggest the participant is finding it difficult to recall that experience. Later in the text, the participant says “nobody asked me any questions about my life” (line 19). This could be coded simply as “health care professionals’ consultation skills”, but that would not reflect how the participant must have felt never to be asked anything about his or her personal life, about the participant as a human being. At the end of this excerpt, the participant just trails off, recalling that no-one showed any interest, which makes for very moving reading. For practitioners in pharmacy, it might also be pertinent to explore the participant’s experience of akathisia and why this was left untreated for 20 years.

One of the questions that arises about qualitative research relates to the reliability of the interpretation and representation of the participants’ narratives. There are no statistical tests that can be used to check reliability and validity as there are in quantitative research. However, work by Lincoln and Guba 11 suggests that there are other ways to “establish confidence in the ‘truth’ of the findings” (p. 218). They call this confidence “trustworthiness” and suggest that there are 4 criteria of trustworthiness: credibility (confidence in the “truth” of the findings), transferability (showing that the findings have applicability in other contexts), dependability (showing that the findings are consistent and could be repeated), and confirmability (the extent to which the findings of a study are shaped by the respondents and not researcher bias, motivation, or interest).

One way of establishing the “credibility” of the coding is to ask another researcher to code the same transcript and then to discuss any similarities and differences in the 2 resulting sets of codes. This simple act can result in revisions to the codes and can help to clarify and confirm the research findings.

Theming refers to the drawing together of codes from one or more transcripts to present the findings of qualitative research in a coherent and meaningful way. For example, there may be examples across participants’ narratives of the way in which they were treated in hospital, such as “not being listened to” or “lack of interest in personal experiences” (see Appendix 1 ). These may be drawn together as a theme running through the narratives that could be named “the patient’s experience of hospital care”. The importance of going through this process is that at its conclusion, it will be possible to present the data from the interviews using quotations from the individual transcripts to illustrate the source of the researchers’ interpretations. Thus, when the findings are organized for presentation, each theme can become the heading of a section in the report or presentation. Underneath each theme will be the codes, examples from the transcripts, and the researcher’s own interpretation of what the themes mean. Implications for real life (e.g., the treatment of people with chronic mental health problems) should also be given.

DATA SYNTHESIS

In this final section of this paper, we describe some ways of drawing together or “synthesizing” research findings to represent, as faithfully as possible, the meaning that participants ascribe to their life experiences. This synthesis is the aim of the final stage of qualitative research. For most readers, the synthesis of data presented by the researcher is of crucial significance—this is usually where “the story” of the participants can be distilled, summarized, and told in a manner that is both respectful to those participants and meaningful to readers. There are a number of ways in which researchers can synthesize and present their findings, but any conclusions drawn by the researchers must be supported by direct quotations from the participants. In this way, it is made clear to the reader that the themes under discussion have emerged from the participants’ interviews and not the mind of the researcher. The work of Latif and others 12 gives an example of how qualitative research findings might be presented.

Planning and Writing the Report

As has been suggested above, if researchers code and theme their material appropriately, they will naturally find the headings for sections of their report. Qualitative researchers tend to report “findings” rather than “results”, as the latter term typically implies that the data have come from a quantitative source. The final presentation of the research will usually be in the form of a report or a paper and so should follow accepted academic guidelines. In particular, the article should begin with an introduction, including a literature review and rationale for the research. There should be a section on the chosen methodology and a brief discussion about why qualitative methodology was most appropriate for the study question and why one particular methodology (e.g., interpretative phenomenological analysis rather than grounded theory) was selected to guide the research. The method itself should then be described, including ethics approval, choice of participants, mode of recruitment, and method of data collection (e.g., semistructured interviews or focus groups), followed by the research findings, which will be the main body of the report or paper. The findings should be written as if a story is being told; as such, it is not necessary to have a lengthy discussion section at the end. This is because much of the discussion will take place around the participants’ quotes, such that all that is needed to close the report or paper is a summary, limitations of the research, and the implications that the research has for practice. As stated earlier, it is not the intention of qualitative research to allow the findings to be generalized, and therefore this is not, in itself, a limitation.

Planning out the way that findings are to be presented is helpful. It is useful to insert the headings of the sections (the themes) and then make a note of the codes that exemplify the thoughts and feelings of your participants. It is generally advisable to put in the quotations that you want to use for each theme, using each quotation only once. After all this is done, the telling of the story can begin as you give your voice to the experiences of the participants, writing around their quotations. Do not be afraid to draw assumptions from the participants’ narratives, as this is necessary to give an in-depth account of the phenomena in question. Discuss these assumptions, drawing on your participants’ words to support you as you move from one code to another and from one theme to the next. Finally, as appropriate, it is possible to include examples from literature or policy documents that add support for your findings. As an exercise, you may wish to code and theme the sample excerpt in Appendix 1 and tell the participant’s story in your own way. Further reading about “doing” qualitative research can be found at the end of this paper.

CONCLUSIONS

Qualitative research can help researchers to access the thoughts and feelings of research participants, which can enable development of an understanding of the meaning that people ascribe to their experiences. It can be used in pharmacy practice research to explore how patients feel about their health and their treatment. Qualitative research has been used by pharmacists to explore a variety of questions and problems (see the “Further Reading” section for examples). An understanding of these issues can help pharmacists and other health care professionals to tailor health care to match the individual needs of patients and to develop a concordant relationship. Doing qualitative research is not easy and may require a complete rethink of how research is conducted, particularly for researchers who are more familiar with quantitative approaches. There are many ways of conducting qualitative research, and this paper has covered some of the practical issues regarding data collection, analysis, and management. Further reading around the subject will be essential to truly understand this method of accessing peoples’ thoughts and feelings to enable researchers to tell participants’ stories.

Appendix 1. Excerpt from a sample transcript

The participant (age late 50s) had suffered from a chronic mental health illness for 30 years. The participant had become a “revolving door patient,” someone who is frequently in and out of hospital. As the participant talked about past experiences, the researcher asked:

  • What was treatment like 30 years ago?
  • Umm—well it was pretty much they could do what they wanted with you because I was put into the er, the er kind of system er, I was just on
  • endless section threes.
  • Really…
  • But what I didn’t realize until later was that if you haven’t actually posed a threat to someone or yourself they can’t really do that but I didn’t know
  • that. So wh-when I first went into hospital they put me on the forensic ward ’cause they said, “We don’t think you’ll stay here we think you’ll just
  • run-run away.” So they put me then onto the acute admissions ward and – er – I can remember one of the first things I recall when I got onto that
  • ward was sitting down with a er a Dr XXX. He had a book this thick [gestures] and on each page it was like three questions and he went through
  • all these questions and I answered all these questions. So we’re there for I don’t maybe two hours doing all that and he asked me he said “well
  • when did somebody tell you then that you have schizophrenia” I said “well nobody’s told me that” so he seemed very surprised but nobody had
  • actually [pause] whe-when I first went up there under police escort erm the senior kind of consultants people I’d been to where I was staying and
  • ermm so er [pause] I . . . the, I can remember the very first night that I was there and given this injection in this muscle here [gestures] and just
  • having dreadful side effects the next day I woke up [pause]
  • . . . and I suffered that akathesia I swear to you, every minute of every day for about 20 years.
  • Oh how awful.
  • And that side of it just makes life impossible so the care on the wards [pause] umm I don’t know it’s kind of, it’s kind of hard to put into words
  • [pause]. Because I’m not saying they were sort of like not friendly or interested but then nobody ever seemed to want to talk about your life [pause]
  • nobody asked me any questions about my life. The only questions that came into was they asked me if I’d be a volunteer for these student exams
  • and things and I said “yeah” so all the questions were like “oh what jobs have you done,” er about your relationships and things and er but
  • nobody actually sat down and had a talk and showed some interest in you as a person you were just there basically [pause] um labelled and you
  • know there was there was [pause] but umm [pause] yeah . . .

This article is the 10th in the CJHP Research Primer Series, an initiative of the CJHP Editorial Board and the CSHP Research Committee. The planned 2-year series is intended to appeal to relatively inexperienced researchers, with the goal of building research capacity among practising pharmacists. The articles, presenting simple but rigorous guidance to encourage and support novice researchers, are being solicited from authors with appropriate expertise.

Previous articles in this series:

Bond CM. The research jigsaw: how to get started. Can J Hosp Pharm . 2014;67(1):28–30.

Tully MP. Research: articulating questions, generating hypotheses, and choosing study designs. Can J Hosp Pharm . 2014;67(1):31–4.

Loewen P. Ethical issues in pharmacy practice research: an introductory guide. Can J Hosp Pharm. 2014;67(2):133–7.

Tsuyuki RT. Designing pharmacy practice research trials. Can J Hosp Pharm . 2014;67(3):226–9.

Bresee LC. An introduction to developing surveys for pharmacy practice research. Can J Hosp Pharm . 2014;67(4):286–91.

Gamble JM. An introduction to the fundamentals of cohort and case–control studies. Can J Hosp Pharm . 2014;67(5):366–72.

Austin Z, Sutton J. Qualitative research: getting started. C an J Hosp Pharm . 2014;67(6):436–40.

Houle S. An introduction to the fundamentals of randomized controlled trials in pharmacy research. Can J Hosp Pharm . 2014; 68(1):28–32.

Charrois TL. Systematic reviews: What do you need to know to get started? Can J Hosp Pharm . 2014;68(2):144–8.

Competing interests: None declared.

Further Reading

Examples of qualitative research in pharmacy practice.

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Qualitative Research in General

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Group Dynamics in Focus Groups

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Social Constructivism

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Collecting Qualitative Data

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Constructivist Grounded Theory

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Pre- and post-White-nose Syndrome Bat Capture Models

These data are the collection of generalized linear mixed models run for AIC comparison of the pre- and post-White-nose Syndrome bat mist-net captures and percent juveniles in capture by year, time since White-nose Syndrome at collection set, U.S Fish and Wildlife Service designated geographic units, states or NABAT grid cell, collection site mean temperature, collection site temperature range and collection site elevation. Models are inclusive of data from 1999-2019 for the little brown bat (Myotis lucifugus), northern long-eared bat (Myotis septentrionalis) and the tri-colored bat (Perimyotis subflavus).

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Publication Year 2024
Title Pre- and post-White-nose Syndrome Bat Capture Models
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Research on enhancing the yield and quality of oat forage: optimization of nitrogen and organic fertilizer management strategies.

research study data collection

1. Introduction

2. materials and methods, 2.1. experimental site, 2.2. experimental material, 2.3. determination indices and methods, 2.4. statistical analysis, 3.1. effect of different fertilizer treatments on photosynthetic characteristics of oats, 3.2. effect on oat forage yield of different fertilizer treatments, 3.3. effect of different fertilizer treatments on oat forage quality, 3.4. correlation analysis of different fertilizer treatments with various indicators of oats, 3.5. multi-criteria decision-making topsis model evaluation, 4. discussion, 4.1. analysis of the impact of fertilizer application rate and period on forage yield and their annual variations, 4.2. effect of different nitrogen fertilizer management on photosynthetic properties, 4.3. a comprehensive study on the improvement of the nutritional quality of oats by combining nitrogen and organic fertilizers, 4.4. studies on the combined effects of fertilizer application on forage yield and quality and their relationship with photosynthetic characteristics, 4.5. the profound impact of strategies on sustainable development: farmers’ practical exploration and research prospects, 5. conclusions, author contributions, data availability statement, acknowledgments, conflicts of interest.

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Click here to enlarge figure

Soil
Type
Total
Nitrogen
g·kg
Total
Phosphorus
g·kg
Total
Potassium
g·kg
Available
Nitrogen
mg·kg
Available
Phosphorus
mg·kg
Available
Potassium
mg·kg
Organic
Matter
g·kg
pH
loam1.872.4623.40106.0027.57290.0034.398.18
TreatmentsBasal Fertilizer (kg·hm )Jointing Fertilizer
N (kg·hm )
Organic FertilizerN
F1D10690
F2D1051.750
F3D1034.50
F4D1450051.750
F5D1450034.50
F1D2020.748.3
F2D2015.52536.225
F3D2010.3524.15
F4D2450015.52536.225
F5D2450010.3524.15
YearsTreatmentsChl/mg·g Pn/μmol·m ·s Tr/μmol·mol Ci/mmol·m ·s Gs/mol·m ·s
2020F1D14.88 ± 0.13d15.82 ± 0.35bc9.93 ± 0.17bc285.20 ± 7.91f334.32 ± 10.62d
F2D13.31 ± 0.42f12.68 ± 0.57efg7.11 ± 0.58ef334.62 ± 9.71bc282.76 ± 5.69fg
F3D12.83 ± 0.06g11.01 ± 0.65g6.49 ± 0.13f378.53 ± 4.00a268.89 ± 11.22g
F4D14.03 ± 0.05e15.31 ± 0.22cd9.06 ± 0.69cd301.47 ± 8.79e303.22 ± 6.28e
F5D12.89 ± 0.02g12.01 ± 0.65fg7.05 ± 1.08ef348.53 ± 12.94b275.38 ± 6.99fg
F1D27.42 ± 0.04a21.68 ± 2.94a12.08 ± 0.85a239.27 ± 5.23h481.41 ± 2.78a
F2D25.27 ± 0.14c15.90 ± 0.22bc10.36 ± 1.05b277.38 ± 3.76f358.89 ± 9.66c
F3D23.78 ± 0.24e13.49 ± 0.43def7.90 ± 0.52de328.53 ± 16.07cd285.47 ± 6.87f
F4D26.18 ± 0.09b17.35 ± 0.38b11.08 ± 0.59ab259.02 ± 4.13g383.17 ± 8.31b
F5D24.08 ± 0.11e14.01 ± 0.65cde8.06 ± 0.69de314.80 ± 5.94de302.47 ± 7.36e
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
Fertilizer period (D)p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
F × Dp < 0.001p = 0.023p = 0.102p = 0.244p < 0.001
2021F1D15.73 ± 0.06e20.08 ± 0.11c16.06 ± 0.36e245.07 ± 0.84e409.43 ± 8.07d
F2D14.39 ± 0.01i15.23 ± 0.44f10.74 ± 0.38h271.41 ± 1.54b333.91 ± 2.40h
F3D14.05 ± 0.05j14.14 ± 0.61g9.37 ± 0.25i307.28 ± 1.86a319.78 ± 3.10i
F4D16.97 ± 0.11c22.90 ± 0.81b18.41 ± 0.30c229.02 ± 4.13g456.50 ± 8.40b
F5D15.42 ± 0.06f19.19 ± 0.96cd15.63 ± 0.68e244.47 ± 3.00e393.19 ± 0.73e
F1D26.15 ± 0.03d22.88 ± 0.08b17.46 ± 0.27d239.27 ± 5.23f434.80 ± 4.48c
F2D25.06 ± 0.11g18.31 ± 0.59d14.14 ± 0.61f252.73 ± 2.83d380.22 ± 6.11f
F3D24.89 ± 0.01h16.44 ± 0.48e12.16 ± 0.22g263.60 ± 1.45c356.53 ± 5.68g
F4D27.85 ± 0.12a24.35 ± 0.38a21.08 ± 0.25a210.60 ± 2.34i481.41 ± 2.78a
F5D27.33 ± 0.20b23.78 ± 0.70ab19.63 ± 0.52b218.05 ± 2.67h462.47 ± 6.83b
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
Fertilizer period (D)p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
F × Dp < 0.001p = 0.003p < 0.001p < 0.001p < 0.001
TreatmentsChl/mg·g Pn/μmol·m ·s Tr/mmol·m ·s Ci/μmol·mol Gs/mol·m ·s
F16.04 ± 0.05b20.12 ± 0.84a13.88 ± 0.16b252.20 ± 0.80c414.99 ± 4.22a
F24.51 ± 0.07d15.33 ± 0.25c10.59 ± 0.22d284.04 ± 2.64b338.94 ± 1.65d
F33.89 ± 0.04e13.77 ± 0.40d8.98 ± 0.14e319.49 ± 2.23a307.66 ± 3.10e
F46.26 ± 0.06a19.98 ± 0.35a14.91 ± 0.06a250.03 ± 3.42c406.08 ± 3.32b
F54.93 ± 0.06c17.25 ± 0.34b12.59 ± 0.32c281.46 ± 4.16b358.38 ± 1.94c
D14.44 ± 0.02b15.84 ± 0.11b10.98 ± 0.16b294.56 ± 2.62a337.74 ± 5.37b
D25.80 ± 0.04a18.82 ± 0.44a13.40 ± 0.13a260.33 ± 0.81b392.68 ± 1.23a
YearsTreatmentsChl/mg·g Pn/μmol·m ·s Tr/mmol·m ·s Ci/μmol·mol Gs/mol·m ·s
2020F1D13.87 ± 0.13d13.41 ± 0.40bc10.16 ± 0.91ab314.02 ± 4.90bc282.88 ± 7.85b
F2D12.53 ± 0.42g11.58 ± 0.27ef6.41 ± 0.48c331.99 ± 2.34a275.38 ± 6.99c
F3D12.05 ± 0.06h10.89 ± 0.44f5.11 ± 0.88d337.47 ± 7.32a268.89 ± 11.22d
F4D13.25 ± 0.05e13.16 ± 0.62bc9.37 ± 0.61b317.11b ± 6.52b358.89 ± 9.66b
F5D12.11 ± 0.02h11.29 ± 0.39ef5.14 ± 0.01d332.74 ± 2.58a303.22 ± 6.28c
F1D26.32 ± 0.04a15.63 ± 1.18a11.01 ± 0.74a307.09 ± 1.94c306.04 ± 1.80a
F2D24.17 ± 0.14c13.71 ± 0.36bc10.47 ± 0.39a313.29 ± 4.09bc298.70 ± 4.31a
F3D22.68 ± 0.24fg12.02 ± 0.28de6.62 ± 0.40c332.14 ± 2.83a275.68 ± 14.27b
F4D25.08 ± 0.09b14.08 ± 0.41b10.78 ± 0.11a307.68 ± 6.30c303.83 ± 2.29a
F5D22.97 ± 0.11ef12.71 ± 0.94cd7.17 ± 0.57c321.23 ± 4.54b276.47 ± 1.75b
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
Fertilizer period (D) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
F × D p < 0.001p = 0.264p = 0.001p = 0.160p < 0.001
2021F1D14.70 ± 0.02d15.10 ± 0.36d10.37 ± 0.25e275.68 ± 2.42e364.71 ± 11.45d
F2D13.76 ± 0.02f10.20 ± 0.82g6.92 ± 0.45g316.63 ± 5.05c296.34 ± 3.20g
F3D13.33 ± 0.11g8.53 ± 0.09h5.18 ± 0.27h327.88 ± 3.63b268.47 ± 7.14h
F4D15.55 ± 0.10c17.77 ± 0.32c12.08 ± 0.76c257.21 ± 1.99f389.13 ± 7.49c
F5D14.35 ± 0.28e14.35 ± 0.51d9.89 ± 0.12e288.88 ± 1.92d344.92 ± 3.09e
F1D25.37 ± 0.26c17.26 ± 0.46c11.19 ± 0.18d266.19 ± 7.47f372.36 ± 9.05d
F2D24.32 ± 0.03e13.20 ± 0.06e8.98 ± 0.12f297.37 ± 3.89d338.56 ± 1.30e
F3D24.17 ± 0.02e11.70 ± 0.63f7.66 ± 0.03g314.47 ± 4.29c320.05 ± 5.57f
F4D27.00 ± 0.12a21.14 ± 0.90a14.74 ± 0.96a215.68 ± 12.64h472.47 ± 10.29a
F5D26.18 ± 0.11b19.11 ± 0.60b13.26 ± 0.49b239.27 ± 5.23g455.08 ± 3.39b
Fertilizer
rate (F)
p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
Fertilizer period (D) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
F × D p < 0.001p = 0.009p = 0.002p < 0.001p < 0.001
TreatmentsChl/mg·g Pn/μmol·m ·s Tr/mmol·m ·s Ci/μmol·mol Gs/mol·m ·s
F15.07 ± 0.11b15.35 ± 0.23b10.68 ± 0.37b290.74 ± 2.76c331.50 ± 6.66b
F23.69 ± 0.07d12.18 ± 0.18d8.20 ± 0.28d314.82 ± 0.82b290.67 ± 0.33c
F33.06 ± 0.03e10.79 ± 0.15e6.14 ± 0.16e327.99 ± 1.78a267.58 ± 4.82d
F45.22 ± 0.05a16.54 ± 0.35a11.74 ± 0.33a274.42 ± 5.50d362.04 ± 5.79a
F53.90 ± 0.09c14.37 ± 0.21c8.86 ± 0.01c295.53 ± 3.42c325.75 ± 2.97b
D13.55 ± 0.03b12.63 ± 0.15b8.06 ± 0.24b309.96 ± 0.77a289.09 ± 2.95b
D24.83 ± 0.05a15.06 ± 0.13a10.18 ± 0.03a291.44 ± 2.78b341.92 ± 2.11a
Period of FertilityItemsdfForage Yield
F-Valuep-Value
Flowering stageFertilizer rate (F)41053.956p < 0.001
Fertilizer period (D)11916.710p < 0.001
Years (Y)1249.825p < 0.001
F × D447.274p < 0.001
F × Y4444.437p < 0.001
D × Y11.460p = 0.234
Milk stageFertilizer rate (F)41882.990p < 0.001
Fertilizer period (D)12426.165p < 0.001
Years (Y)146.888p < 0.001
F × D441.886p < 0.001
F × Y4623.328p < 0.001
D × Y1232.622p < 0.001
ItemsTreatmentsForage Yield/kg·hm
Flowering StageMilk Stage
Fertilizer rateF110,921.78 ± 77.68b14,428.00 ± 145.44b
F29449.08 ± 36.61d11,593.47 ± 66.97d
F38356.61 ± 40.07e9919.31 ± 118.19e
F412,426.42 ± 90.02a14,722.48 ± 70.60a
F510,347.83 ± 21.81c12,642.54 ± 22.06c
Fertilizer periodD19375.27 ± 31.18b11,644.98 ± 20.92b
D211,225.42 ± 18.21a13,677.34 ± 81.51a
Years20209966.37 ± 31.18b10,934.98 ± 50.59b
202110,634.32 ± 51.78a13,257.34 ± 75.00a
YearsTreatmentsCP%ADF/%NDF/%CF/%EE/%
2020F1D110.59 ± 0.23d22.17 ± 0.35g37.36 ± 0.49g22.70 ± 0.42g1.30 ± 0.17abc
F2D18.75 ± 0.22g29.27 ± 0.21c47.84 ± 0.41c32.68 ± 0.76c1.27 ± 0.25abc
F3D17.68 ± 0.07i34.41 ± 0.24a53.06 ± 0.70a36.78 ± 0.64a0.95 ± 0.35bc
F4D19.87 ± 0.08e24.04 ± 0.55f39.63 ± 0.29f24.98 ± 0.15f1.03 ± 0.23bc
F5D18.16 ± 0.14h31.87 ± 0.18b49.44 ± 0.90b35.76 ± 0.37b1.02 ± 0.25bc
F1D213.28 ± 0.16a16.18 ± 0.69j30.70 ± 0.40j16.01 ± 0.66j1.77 ± 0.54a
F2D211.82 ± 0.03c20.03 ± 0.44h35.85 ± 0.34h20.65 ± 0.85h1.53 ± 0.41ab
F3D29.25 ± 0.09f28.46 ± 0.18d44.12 ± 0.60d30.45 ± 0.31d0.90 ± 0.43c
F4D212.83 ± 0.14b18.65 ± 0.44i33.21 ± 0.80i18.89 ± 0.66i1.54 ± 0.27ab
F5D29.32 ± 0.08f26.61 ± 0.46e41.96 ± 0.76e27.31 ± 0.80e0.99 ± 0.08bc
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p = 0.067
Fertilizer period (D) p < 0.001p < 0.001p < 0.001p < 0.001p = 0.020
F × D p < 0.001p < 0.001p < 0.001p < 0.001p = 0.424
2021F1D113.65 ± 0.05d19.25 ± 0.22f38.87 ± 0.09f21.86 ± 0.05f1.74 ± 0.34d
F2D19.67 ± 0.06g28.97 ± 0.09b50.62 ± 0.14b30.71 ± 0.13b1.32 ± 0.17d
F3D18.31 ± 0.09h31.42 ± 0.10a53.84 ± 0.23a33.44 ± 0.13a1.32 ± 0.18d
F4D114.28 ± 0.60bc16.85 ± 0.34h32.37 ± 0.27h16.21 ± 0.05h2.56 ± 0.10bc
F5D111.50 ± 0.61e22.19 ± 0.49e40.56 ± 0.25e23.10 ± 0.13e1.48 ± 0.20d
F1D214.06 ± 0.09cd17.42 ± 0.37g35.12 ± 0.19g19.44 ± 0.27g2.21 ± 0.12c
F2D210.51 ± 0.15f23.36 ± 0.19d42.88 ± 0.08d25.19 ± 0.21d1.43 ± 0.22d
F3D29.98 ± 0.19g25.84 ± 0.34c47.53 ± 0.42c27.83 ± 0.13c1.33 ± 0.25d
F4D214.92 ± 0.12a15.51 ± 0.24i28.57 ± 0.26j14.69 ± 0.43j3.77 ± 0.45a
F5D214.59 ± 0.03ab16.68 ± 0.02h30.14 ± 0.17i15.61 ± 0.06i2.99 ± 0.06b
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
Fertilizer period (D) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
F × D p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
TreatmentsCP/%ADF/%NDF/%CF/%EE/%
F112.89 ± 0.04a18.76 ± 0.33d35.51 ± 0.10d20.01 ± 0.26d1.75 ± 0.02b
F210.19 ± 0.06b25.41 ± 0.12b44.29 ± 0.20b27.31 ± 0.27b1.39 ± 0.13c
F38.80 ± 0.05c30.03 ± 0.10a49.64 ± 0.09a32.12 ± 0.22a1.12 ± 0.06c
F412.97 ± 0.16a18.76 ± 0.17d33.44 ± 0.25e18.69 ± 0.17e2.22 ± 0.19a
F510.89 ± 0.11d24.34 ± 0.22c40.53 ± 0.07c25.45 ± 0.33c1.62 ± 0.14b
D110.25 ± 0.12b26.04 ± 0.10a44.36 ± 0.16a28.82 ± 0.13a1.40 ± 0.08b
D212.06 ± 0.02a20.87 ± 0.10b37.00 ± 0.22b21.94 ± 0.10b1.85 ± 0.11a
YearsTreatmentsCP%ADF/%NDF/%CF/%EE/%
2020F1D19.69 ± 0.21d37.46 ± 0.22e52.81 ± 0.56g27.68 ± 0.29g1.76 ± 0.33abc
F2D18.42 ± 0.09h41.75 ± 1.05c62.36 ± 0.99c38.70 ± 0.42c1.10 ± 0.42d
F3D17.25 ± 0.05j45.28 ± 0.52a68.17 ± 0.80a42.01 ± 0.49a1.80 ± 0.17abc
F4D19.49 ± 0.04e34.97 ± 0.12f54.75 ± 0.26f30.03 ± 0.37f1.62 ± 0.21bcd
F5D18.06 ± 0.09i43.17 ± 0.23b66.12 ± 0.42b40.78 ± 0.81b1.50 ± 0.17bcd
F1D212.67 ± 0.09a25.89 ± 0.05i45.96 ± 0.85j21.23 ± 0.51j2.30 ± 0.53a
F2D211.40 ± 0.06c30.46 ± 0.20g51.26 ± 0.54h25.79 ± 0.25h1.77 ± 0.46abc
F3D28.80 ± 0.11g40.59 ± 0.32d58.87 ± 0.92d35.55 ± 0.36d1.40 ± 0.43bcd
F4D212.37 ± 0.13b27.51 ± 0.24h48.06 ± 0.43i23.75 ± 0.62i2.02 ± 0.27ab
F5D29.04 ± 0.11f37.67 ± 0.41e57.18 ± 0.20e32.20 ± 0.80e1.26 ± 0.43cd
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p = 1.161
Fertilizer period (D) p < 0.001p < 0.001p < 0.001p < 0.001p = 0.029
F × D p < 0.001p < 0.001p < 0.001p < 0.001p = 0.064
2021F1D111.87 ± 0.21e23.83 ± 0.19f41.19 ± 0.39f25.82 ± 0.10e2.33 ± 0.38d
F2D17.81 ± 0.18i32.33 ± 0.20b53.82 ± 0.14b32.31 ± 0.20b1.53 ± 0.08ef
F3D16.38 ± 0.17j36.49 ± 0.12a56.56 ± 0.29a35.37 ± 0.28a1.08 ± 0.13g
F4D113.10 ± 0.35c21.57 ± 0.45g35.79 ± 0.20h21.59 ± 0.34g3.01 ± 0.10c
F5D110.07 ± 0.58f27.04 ± 0.06e43.45 ± 0.39e25.40 ± 0.19e1.93 ± 0.20e
F1D212.57 ± 0.10d21.87 ± 0.96g38.61 ± 0.49g23.22 ± 0.39f2.66 ± 0.12cd
F2D29.38 ± 0.10g28.63 ± 0.19d45.35 ± 0.50d27.83 ± 0.06d1.88 ± 0.22e
F3D28.71 ± 0.16h30.39 ± 0.34c50.48 ± 0.39c29.34 ± 0.23c1.78 ± 0.25e
F4D214.35 ± 0.03a20.34 ± 0.35h31.45 ± 0.10j17.43 ± 0.26i4.22 ± 0.45a
F5D213.70 ± 0.05b20.05 ± 1.70h33.38 ± 0.33i19.34 ± 0.29h3.44 ± 0.06b
Fertilizer rate (F) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
Fertilizer period (D) p < 0.001p < 0.001p < 0.001p < 0.001p < 0.001
F × D p < 0.001p < 0.001p < 0.001p < 0.001p = 0.001
TreatmentsCP/%ADF/%NDF/%CF/%EE/%
F111.70 ± 0.09b27.27 ± 0.24d44.64 ± 0.29d24.49 ± 0.20d2.26 ± 0.16b
F29.25 ± 0.04d33.29 ± 0.21b53.20 ± 0.22b31.16 ± 0.18b1.57 ± 0.07c
F37.78 ± 0.03e38.19 ± 0.12a58.52 ± 0.25a35.57 ± 0.14a1.52 ± 0.11c
F412.33 ± 0.09a26.10 ± 0.13e42.51 ± 0.07e23.20 ± 0.14e2.72 ± 0.05a
F510.22 ± 0.14c31.98 ± 0.46c50.03 ± 0.16c29.43 ± 0.37c2.04 ± 0.11b
D19.21 ± 0.05b34.39 ± 0.04a53.50 ± 0.19a32.67 ± 0.09a1.77 ± 0.09b
D211.30 ± 0.05a28.34 ± 0.08b46.06 ± 0.08b25.57 ± 0.21b2.27 ± 0.07a
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Share and Cite

Duan, L.; Ju, Z.; Ma, X.; Pan, J.; Mustafa, A.E.-Z.M.A.; Jia, Z. Research on Enhancing the Yield and Quality of Oat Forage: Optimization of Nitrogen and Organic Fertilizer Management Strategies. Agronomy 2024 , 14 , 1406. https://doi.org/10.3390/agronomy14071406

Duan L, Ju Z, Ma X, Pan J, Mustafa AE-ZMA, Jia Z. Research on Enhancing the Yield and Quality of Oat Forage: Optimization of Nitrogen and Organic Fertilizer Management Strategies. Agronomy . 2024; 14(7):1406. https://doi.org/10.3390/agronomy14071406

Duan, Lianxue, Zeliang Ju, Xiang Ma, Jing Pan, Abd El-Zaher M. A. Mustafa, and Zhifeng Jia. 2024. "Research on Enhancing the Yield and Quality of Oat Forage: Optimization of Nitrogen and Organic Fertilizer Management Strategies" Agronomy 14, no. 7: 1406. https://doi.org/10.3390/agronomy14071406

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    Data collection is the process of collecting and evaluating information or data from multiple sources to find answers to research problems, answer questions, evaluate outcomes, and forecast trends and probabilities. It is an essential phase in all types of research, analysis, and decision-making, including that done in the social sciences ...

  20. What Is a Research Design

    A research design is a strategy for answering your research question using empirical data. Creating a research design means making decisions about: Your overall research objectives and approach. Whether you'll rely on primary research or secondary research. Your sampling methods or criteria for selecting subjects. Your data collection methods.

  21. Research Design, Data Collection, and Analysis Plan: Version 1.1: The

    HUD's Evaluation Policy states, under the principle of transparency, that "If the findings of a HUD evaluation will have broad public interest and includes a counterfactual, PD&R will publish a synopsis of the research design, data collection and analysis plan soon after it is approved…"

  22. A Practical Guide to Writing Quantitative and Qualitative Research

    - This involves data collection from study participants or the literature regarding a phenomenon of interest, using the collected data to develop a formal hypothesis, and using the formal hypothesis as a framework for testing the hypothesis. ... Many research studies have floundered because the development of research questions and subsequent ...

  23. <em>Health Services Research</em>

    Secondary discharge data from 2011 to 2019 from Texas. Study Design. We conducted a retrospective study estimating the effects of the ACA Marketplace using difference-in-difference regressions, with the main outcome being the uninsured discharge rate. We stratified our sample by patient's race, age, gender, urbanicity, major diagnostic ...

  24. Doing, being, becoming and belonging in forging professional identity

    Whitcombe's (2013) qualitative research study exploring the relationship between problem-based learning and the professional identity of 20 occupational therapy students found that ... recruited participants, completed data collection and analysis, and wrote up the results. Channine Clarke supervised the research throughout. Both authors then ...

  25. Markets for Diversifying Agriculture: Case Studies of the U.S Midwest

    The data collection period spanned from October 2022 to February 2024. Interviews with 29 stakeholders, including farmers, industry representatives, agricultural cooperatives, and non-profits, provided insights into diversified agriculture practices.Each case study provides in-depth insights into the opportunities, challenges, and key drivers ...

  26. Health Sciences Clinical One Data Collection

    Clinical Research; Oracle Health Sciences Clinical One Data Collection. Oracle Health Sciences Clinical One Data Collection goes beyond electronic data capture, allowing you to collect datasets from any source and harmonize them in a single place to draw valuable clinical insight. ... Transformative digital strategies are needed for faster ...

  27. Qualitative Research: Data Collection, Analysis, and Management

    In this article, we review some principles of the collection, analysis, and management of qualitative data to help pharmacists interested in doing research in their practice to continue their learning in this area. Qualitative research can help researchers to access the thoughts and feelings of research participants, which can enable ...

  28. Full article: Gut microbial features and dietary fiber intake predict

    All human-related procedures and sample and data collection were approved by the Cornell University Institutional Review Board for Human Participant Research (Protocol Number: 1902008575) prior to recruitment and enrollment of participants. Study participants included healthy males and healthy, non-pregnant or lactating females 18-59 years old.

  29. Pre- and post-White-nose Syndrome Bat Capture Models

    These data are the collection of generalized linear mixed models run for AIC comparison of the pre- and post-White-nose Syndrome bat mist-net captures and percent juveniles in capture by year, time since White-nose Syndrome at collection set, U.S Fish and Wildlife Service designated geographic units, states or NABAT grid cell, collection site mean temperature, collection site temperature range and

  30. Research on Enhancing the Yield and Quality of Oat Forage ...

    In the context of the increasingly serious issues of resource waste, soil degradation, and environmental pollution caused by excessive nitrogen fertilizer application worldwide, this study conducted a two-year field experiment in Qinghai Province to explore suitable nitrogen fertilizer management strategies for the region. Ten fertilization levels were set, incorporating varying ratios of ...