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Qualitative Market Research

ISSN : 1352-2752

Article publication date: 12 September 2016

Qualitative researchers have been criticised for not justifying sample size decisions in their research. This short paper addresses the issue of which sample sizes are appropriate and valid within different approaches to qualitative research.

Design/methodology/approach

The sparse literature on sample sizes in qualitative research is reviewed and discussed. This examination is informed by the personal experience of the author in terms of assessing, as an editor, reviewer comments as they relate to sample size in qualitative research. Also, the discussion is informed by the author’s own experience of undertaking commercial and academic qualitative research over the last 31 years.

In qualitative research, the determination of sample size is contextual and partially dependent upon the scientific paradigm under which investigation is taking place. For example, qualitative research which is oriented towards positivism, will require larger samples than in-depth qualitative research does, so that a representative picture of the whole population under review can be gained. Nonetheless, the paper also concludes that sample sizes involving one single case can be highly informative and meaningful as demonstrated in examples from management and medical research. Unique examples of research using a single sample or case but involving new areas or findings that are potentially highly relevant, can be worthy of publication. Theoretical saturation can also be useful as a guide in designing qualitative research, with practical research illustrating that samples of 12 may be cases where data saturation occurs among a relatively homogeneous population.

Practical implications

Sample sizes as low as one can be justified. Researchers and reviewers may find the discussion in this paper to be a useful guide to determining and critiquing sample size in qualitative research.

Originality/value

Sample size in qualitative research is always mentioned by reviewers of qualitative papers but discussion tends to be simplistic and relatively uninformed. The current paper draws attention to how sample sizes, at both ends of the size continuum, can be justified by researchers. This will also aid reviewers in their making of comments about the appropriateness of sample sizes in qualitative research.

  • Qualitative research
  • Qualitative methodology
  • Case studies
  • Sample size

Boddy, C.R. (2016), "Sample size for qualitative research", Qualitative Market Research , Vol. 19 No. 4, pp. 426-432. https://doi.org/10.1108/QMR-06-2016-0053

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Sample Size Policy for Qualitative Studies Using In-Depth Interviews

  • Published: 12 September 2012
  • Volume 41 , pages 1319–1320, ( 2012 )

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sample size of a qualitative research

  • Shari L. Dworkin 1  

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In recent years, there has been an increase in submissions to the Journal that draw on qualitative research methods. This increase is welcome and indicates not only the interdisciplinarity embraced by the Journal (Zucker, 2002 ) but also its commitment to a wide array of methodologies.

For those who do select qualitative methods and use grounded theory and in-depth interviews in particular, there appear to be a lot of questions that authors have had recently about how to write a rigorous Method section. This topic will be addressed in a subsequent Editorial. At this time, however, the most common question we receive is: “How large does my sample size have to be?” and hence I would like to take this opportunity to answer this question by discussing relevant debates and then the policy of the Archives of Sexual Behavior . Footnote 1

The sample size used in qualitative research methods is often smaller than that used in quantitative research methods. This is because qualitative research methods are often concerned with garnering an in-depth understanding of a phenomenon or are focused on meaning (and heterogeneities in meaning )—which are often centered on the how and why of a particular issue, process, situation, subculture, scene or set of social interactions. In-depth interview work is not as concerned with making generalizations to a larger population of interest and does not tend to rely on hypothesis testing but rather is more inductive and emergent in its process. As such, the aim of grounded theory and in-depth interviews is to create “categories from the data and then to analyze relationships between categories” while attending to how the “lived experience” of research participants can be understood (Charmaz, 1990 , p. 1162).

There are several debates concerning what sample size is the right size for such endeavors. Most scholars argue that the concept of saturation is the most important factor to think about when mulling over sample size decisions in qualitative research (Mason, 2010 ). Saturation is defined by many as the point at which the data collection process no longer offers any new or relevant data. Another way to state this is that conceptual categories in a research project can be considered saturated “when gathering fresh data no longer sparks new theoretical insights, nor reveals new properties of your core theoretical categories” (Charmaz, 2006 , p. 113). Saturation depends on many factors and not all of them are under the researcher’s control. Some of these include: How homogenous or heterogeneous is the population being studied? What are the selection criteria? How much money is in the budget to carry out the study? Are there key stratifiers (e.g., conceptual, demographic) that are critical for an in-depth understanding of the topic being examined? What is the timeline that the researcher faces? How experienced is the researcher in being able to even determine when she or he has actually reached saturation (Charmaz, 2006 )? Is the author carrying out theoretical sampling and is, therefore, concerned with ensuring depth on relevant concepts and examining a range of concepts and characteristics that are deemed critical for emergent findings (Glaser & Strauss, 1967 ; Strauss & Corbin, 1994 , 2007 )?

While some experts in qualitative research avoid the topic of “how many” interviews “are enough,” there is indeed variability in what is suggested as a minimum. An extremely large number of articles, book chapters, and books recommend guidance and suggest anywhere from 5 to 50 participants as adequate. All of these pieces of work engage in nuanced debates when responding to the question of “how many” and frequently respond with a vague (and, actually, reasonable) “it depends.” Numerous factors are said to be important, including “the quality of data, the scope of the study, the nature of the topic, the amount of useful information obtained from each participant, the use of shadowed data, and the qualitative method and study designed used” (Morse, 2000 , p. 1). Others argue that the “how many” question can be the wrong question and that the rigor of the method “depends upon developing the range of relevant conceptual categories, saturating (filling, supporting, and providing repeated evidence for) those categories,” and fully explaining the data (Charmaz, 1990 ). Indeed, there have been countless conferences and conference sessions on these debates, reports written, and myriad publications are available as well (for a compilation of debates, see Baker & Edwards, 2012 ).

Taking all of these perspectives into account, the Archives of Sexual Behavior is putting forward a policy for authors in order to have more clarity on what is expected in terms of sample size for studies drawing on grounded theory and in-depth interviews. The policy of the Archives of Sexual Behavior will be that it adheres to the recommendation that 25–30 participants is the minimum sample size required to reach saturation and redundancy in grounded theory studies that use in-depth interviews. This number is considered adequate for publications in journals because it (1) may allow for thorough examination of the characteristics that address the research questions and to distinguish conceptual categories of interest, (2) maximizes the possibility that enough data have been collected to clarify relationships between conceptual categories and identify variation in processes, and (3) maximizes the chances that negative cases and hypothetical negative cases have been explored in the data (Charmaz, 2006 ; Morse, 1994 , 1995 ).

The Journal does not want to paradoxically and rigidly quantify sample size when the endeavor at hand is qualitative in nature and the debates on this matter are complex. However, we are providing this practical guidance. We want to ensure that more of our submissions have an adequate sample size so as to get closer to reaching the goal of saturation and redundancy across relevant characteristics and concepts. The current recommendation that is being put forward does not include any comment on other qualitative methodologies, such as content and textual analysis, participant observation, focus groups, case studies, clinical cases or mixed quantitative–qualitative methods. The current recommendation also does not apply to phenomenological studies or life history approaches. The current guidance is intended to offer one clear and consistent standard for research projects that use grounded theory and draw on in-depth interviews.

Editor’s note: Dr. Dworkin is an Associate Editor of the Journal and is responsible for qualitative submissions.

Baker, S. E., & Edwards, R. (2012). How many qualitative interviews is enough? National Center for Research Methods. Available at: http://eprints.ncrm.ac.uk/2273/ .

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Morse, J. M. (1994). Designing funded qualitative research. In N. Denzin & Y. Lincoln (Eds.), Handbook of qualitative research (pp. 220–235). Thousand Oaks, CA: Sage Publications.

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Dworkin, S.L. Sample Size Policy for Qualitative Studies Using In-Depth Interviews. Arch Sex Behav 41 , 1319–1320 (2012). https://doi.org/10.1007/s10508-012-0016-6

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Published : 12 September 2012

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InterQ Research

How to Justify Sample Size in Qualitative Research

InterQ Research Explains How To Justify Sample Size In Qualitative Research

  • March 21, 2023

Article Summary : Sample sizes in qualitative research can be much lower than sample sizes in quantitative research. The key is having the right participant segmentation and study design. Data saturation is also a key principle to understand.

Qualitative research is a bit of a puzzle for new practitioners: since it is done via interviewing participants, observation, or studying people’s patterns and movements (in the case of user experience design), one can’t obviously have a huge sample size that is statistically significant. Interviewing 200+ people is not only incredibly time-consuming, it’s also quite expensive.

And, moreover, the goal of qualitative research is not to understand how much or how many. The goal is to collect themes and see patterns. It’s to uncover the “why” versus the amount.

So in this post, we’re going to explore the question every qualitative researcher asks, at one point or another: How do you justify the sample size in qualitative research?

Here are some guidelines.

Qualitative sample size guideline #1: Segmentation of participants

In qualitative research, because the goal is to understand themes and patterns of a particular subset (versus a broad population), the first step is segmentation. You may also know of this as “ persona ” development, but regardless of what you call it, the idea is to first bucket your various buyer/customer types into like-categories. For example, if you’re selling sales software, your target isn’t every single company who sells products. It’s likely much more specific: like mid-market sized VP-level sales execs who have a technology product and use a cloud-based CRM. If that’s your main buyer, that’s your segment who you would focus on in qualitative research.

Generally, most companies have multiple targets, so the trick is to think about all the various buyers/consumers and identify which underlying traits they have in common, as well as which traits differentiate them from other targets. Typically, this is where quantitative data comes into play: either through internal data analysis or surveys. Whatever your process, this is step 1 to figure out the segments you will be bucketing participants into so you can move into the qualitative phase, where you’ll ask in-depth questions, via interviews, to each segment category. At this stage, it’s time to bring in your recruiting company to find your participants.

Qualitative sample size guideline #2: Figure out the appropriate study design

After you’ve tackled your segmentation exercise and know how to divide up your participants, you’ll need to think through the qualitative methodology that is most appropriate for answering your research questions. At InterQ Research, we always design studies through the lens of contextual research. This means that you want to set up your studies to be as close to real life as possible. Is your product sale done through a group discussion or individual decision? Often, when teams decide on software or technology stacks, they’ll want to test it and talk amongst themselves. If this is the case, you would need to interview the team or a team of like-minded professionals to see how they come to a decision. In this case, focus groups would be a great methodology.

Conversely, if your product is thought through on an individual-basis, like, perhaps, a person navigating a website when purchasing a plane ticket, then you’d want to interview the individual, alone. In this case, you’d want to choose a hybrid approach, of a user experience/journey mapping exercise, along with an in-depth interview.

In qualitative research, there are numerous methodologies, and frequently, mixed-methodologies work best, in order to see the context of how people behave, as well as to understand how they think.

But I digress. Let’s get back to sample sizes in qualitative research.

Qualitative sample size guideline #3: Your sample size is completed when you reach saturation

So far we’ve covered how to first segment your audiences, and then we’ve talked about the methodology to choose, based on context. The third principle in qualitative research is to understand the theory of data saturation.

Saturation in qualitative research means that, when interviewing a distinct segment of participants, you are able to explore all of the common themes the sample set has in common. In other words, after doing, let’s say, 15 interviews about a specific topic, you start to hear the participants all say similar things. Since you have a fairly homogenous sample, these themes will start to come out after 10-20 interviews, if you’ve done your recruiting well (and sometimes as soon as 6 interviews). Once you hear the same themes, with no new information, this is data saturation.

The beauty of qualitative research is that if you:

  • Segment your audiences carefully, into distinct groups, and,
  • Choose the right methodology

You’ll start to hit saturation, and you will get diminishing returns with more interviews. In this manner, qualitative research can have smaller sample sizes than quantitative, since it’s thematic, versus statistical.

Let’s wrap it up: So what is the ideal sample size in qualitative research?

To bring this one home, let’s answer the question we sought out to investigate: the sample size in qualitative research.

Typically, sample sizes will range from 6-20, per segment. (So if you have 5 segments, 6 is your multiplier for the total number you’ll need, so you would have a total sample size of 30.) For very specific tasks, such as in user experience research, moderators will see the same themes after as few as 5-6 interviews. In most studies, though, researchers will reach saturation after 10-20 interviews. The variable here depends on how homogenous the sample is, as well as the type of questions being asked. Some researchers aim for a bakers dozen (13), and see if they’ve reached saturation after 13. If not, the study can be expanded to find more participants so that all the themes can be explored. But 13 is a good place to start.

Interested in running a qualitative research study? Request a proposal > 

Author Bio: Joanna Jones is the founder and CEO of InterQ Research. At InterQ, she oversees study design, manages clients, and moderators studies.

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Sample size in qualitative research

Affiliation.

  • 1 Department of Women's and Children's Health, School of Nursing, University of North Carolina at Chapel Hill 27599-7460, USA.
  • PMID: 7899572
  • DOI: 10.1002/nur.4770180211

A common misconception about sampling in qualitative research is that numbers are unimportant in ensuring the adequacy of a sampling strategy. Yet, simple sizes may be too small to support claims of having achieved either informational redundancy or theoretical saturation, or too large to permit the deep, case-oriented analysis that is the raison-d'être of qualitative inquiry. Determining adequate sample size in qualitative research is ultimately a matter of judgment and experience in evaluating the quality of the information collected against the uses to which it will be put, the particular research method and purposeful sampling strategy employed, and the research product intended.

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  • Sample Size

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Sample Size and its Importance in Research

Chittaranjan andrade.

Clinical Psychopharmacology Unit, Department of Clinical Psychopharmacology and Neurotoxicology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India

The sample size for a study needs to be estimated at the time the study is proposed; too large a sample is unnecessary and unethical, and too small a sample is unscientific and also unethical. The necessary sample size can be calculated, using statistical software, based on certain assumptions. If no assumptions can be made, then an arbitrary sample size is set for a pilot study. This article discusses sample size and how it relates to matters such as ethics, statistical power, the primary and secondary hypotheses in a study, and findings from larger vs. smaller samples.

Studies are conducted on samples because it is usually impossible to study the entire population. Conclusions drawn from samples are intended to be generalized to the population, and sometimes to the future as well. The sample must therefore be representative of the population. This is best ensured by the use of proper methods of sampling. The sample must also be adequate in size – in fact, no more and no less.

SAMPLE SIZE AND ETHICS

A sample that is larger than necessary will be better representative of the population and will hence provide more accurate results. However, beyond a certain point, the increase in accuracy will be small and hence not worth the effort and expense involved in recruiting the extra patients. Furthermore, an overly large sample would inconvenience more patients than might be necessary for the study objectives; this is unethical. In contrast, a sample that is smaller than necessary would have insufficient statistical power to answer the primary research question, and a statistically nonsignificant result could merely be because of inadequate sample size (Type 2 or false negative error). Thus, a small sample could result in the patients in the study being inconvenienced with no benefit to future patients or to science. This is also unethical.

In this regard, inconvenience to patients refers to the time that they spend in clinical assessments and to the psychological and physical discomfort that they experience in assessments such as interviews, blood sampling, and other procedures.

ESTIMATING SAMPLE SIZE

So how large should a sample be? In hypothesis testing studies, this is mathematically calculated, conventionally, as the sample size necessary to be 80% certain of identifying a statistically significant outcome should the hypothesis be true for the population, with P for statistical significance set at 0.05. Some investigators power their studies for 90% instead of 80%, and some set the threshold for significance at 0.01 rather than 0.05. Both choices are uncommon because the necessary sample size becomes large, and the study becomes more expensive and more difficult to conduct. Many investigators increase the sample size by 10%, or by whatever proportion they can justify, to compensate for expected dropout, incomplete records, biological specimens that do not meet laboratory requirements for testing, and other study-related problems.

Sample size calculations require assumptions about expected means and standard deviations, or event risks, in different groups; or, upon expected effect sizes. For example, a study may be powered to detect an effect size of 0.5; or a response rate of 60% with drug vs. 40% with placebo.[ 1 ] When no guesstimates or expectations are possible, pilot studies are conducted on a sample that is arbitrary in size but what might be considered reasonable for the field.

The sample size may need to be larger in multicenter studies because of statistical noise (due to variations in patient characteristics, nonspecific treatment characteristics, rating practices, environments, etc. between study centers).[ 2 ] Sample size calculations can be performed manually or using statistical software; online calculators that provide free service can easily be identified by search engines. G*Power is an example of a free, downloadable program for sample size estimation. The manual and tutorial for G*Power can also be downloaded.

PRIMARY AND SECONDARY ANALYSES

The sample size is calculated for the primary hypothesis of the study. What is the difference between the primary hypothesis, primary outcome and primary outcome measure? As an example, the primary outcome may be a reduction in the severity of depression, the primary outcome measure may be the Montgomery-Asberg Depression Rating Scale (MADRS) and the primary hypothesis may be that reduction in MADRS scores is greater with the drug than with placebo. The primary hypothesis is tested in the primary analysis.

Studies almost always have many hypotheses; for example, that the study drug will outperform placebo on measures of depression, suicidality, anxiety, disability and quality of life. The sample size necessary for adequate statistical power to test each of these hypotheses will be different. Because a study can have only one sample size, it can be powered for only one outcome, the primary outcome. Therefore, the study would be either overpowered or underpowered for the other outcomes. These outcomes are therefore called secondary outcomes, and are associated with secondary hypotheses, and are tested in secondary analyses. Secondary analyses are generally considered exploratory because when many hypotheses in a study are each tested at a P < 0.05 level for significance, some may emerge statistically significant by chance (Type 1 or false positive errors).[ 3 ]

INTERPRETING RESULTS

Here is an interesting question. A test of the primary hypothesis yielded a P value of 0.07. Might we conclude that our sample was underpowered for the study and that, had our sample been larger, we would have identified a significant result? No! The reason is that larger samples will more accurately represent the population value, whereas smaller samples could be off the mark in either direction – towards or away from the population value. In this context, readers should also note that no matter how small the P value for an estimate is, the population value of that estimate remains the same.[ 4 ]

On a parting note, it is unlikely that population values will be null. That is, for example, that the response rate to the drug will be exactly the same as that to placebo, or that the correlation between height and age at onset of schizophrenia will be zero. If the sample size is large enough, even such small differences between groups, or trivial correlations, would be detected as being statistically significant. This does not mean that the findings are clinically significant.

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There are no conflicts of interest.

  • Research article
  • Open access
  • Published: 21 November 2018

Characterising and justifying sample size sufficiency in interview-based studies: systematic analysis of qualitative health research over a 15-year period

  • Konstantina Vasileiou   ORCID: orcid.org/0000-0001-5047-3920 1 ,
  • Julie Barnett 1 ,
  • Susan Thorpe 2 &
  • Terry Young 3  

BMC Medical Research Methodology volume  18 , Article number:  148 ( 2018 ) Cite this article

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Choosing a suitable sample size in qualitative research is an area of conceptual debate and practical uncertainty. That sample size principles, guidelines and tools have been developed to enable researchers to set, and justify the acceptability of, their sample size is an indication that the issue constitutes an important marker of the quality of qualitative research. Nevertheless, research shows that sample size sufficiency reporting is often poor, if not absent, across a range of disciplinary fields.

A systematic analysis of single-interview-per-participant designs within three health-related journals from the disciplines of psychology, sociology and medicine, over a 15-year period, was conducted to examine whether and how sample sizes were justified and how sample size was characterised and discussed by authors. Data pertinent to sample size were extracted and analysed using qualitative and quantitative analytic techniques.

Our findings demonstrate that provision of sample size justifications in qualitative health research is limited; is not contingent on the number of interviews; and relates to the journal of publication. Defence of sample size was most frequently supported across all three journals with reference to the principle of saturation and to pragmatic considerations. Qualitative sample sizes were predominantly – and often without justification – characterised as insufficient (i.e., ‘small’) and discussed in the context of study limitations. Sample size insufficiency was seen to threaten the validity and generalizability of studies’ results, with the latter being frequently conceived in nomothetic terms.

Conclusions

We recommend, firstly, that qualitative health researchers be more transparent about evaluations of their sample size sufficiency, situating these within broader and more encompassing assessments of data adequacy . Secondly, we invite researchers critically to consider how saturation parameters found in prior methodological studies and sample size community norms might best inform, and apply to, their own project and encourage that data adequacy is best appraised with reference to features that are intrinsic to the study at hand. Finally, those reviewing papers have a vital role in supporting and encouraging transparent study-specific reporting.

Peer Review reports

Sample adequacy in qualitative inquiry pertains to the appropriateness of the sample composition and size . It is an important consideration in evaluations of the quality and trustworthiness of much qualitative research [ 1 ] and is implicated – particularly for research that is situated within a post-positivist tradition and retains a degree of commitment to realist ontological premises – in appraisals of validity and generalizability [ 2 , 3 , 4 , 5 ].

Samples in qualitative research tend to be small in order to support the depth of case-oriented analysis that is fundamental to this mode of inquiry [ 5 ]. Additionally, qualitative samples are purposive, that is, selected by virtue of their capacity to provide richly-textured information, relevant to the phenomenon under investigation. As a result, purposive sampling [ 6 , 7 ] – as opposed to probability sampling employed in quantitative research – selects ‘information-rich’ cases [ 8 ]. Indeed, recent research demonstrates the greater efficiency of purposive sampling compared to random sampling in qualitative studies [ 9 ], supporting related assertions long put forward by qualitative methodologists.

Sample size in qualitative research has been the subject of enduring discussions [ 4 , 10 , 11 ]. Whilst the quantitative research community has established relatively straightforward statistics-based rules to set sample sizes precisely, the intricacies of qualitative sample size determination and assessment arise from the methodological, theoretical, epistemological, and ideological pluralism that characterises qualitative inquiry (for a discussion focused on the discipline of psychology see [ 12 ]). This mitigates against clear-cut guidelines, invariably applied. Despite these challenges, various conceptual developments have sought to address this issue, with guidance and principles [ 4 , 10 , 11 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], and more recently, an evidence-based approach to sample size determination seeks to ground the discussion empirically [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ].

Focusing on single-interview-per-participant qualitative designs, the present study aims to further contribute to the dialogue of sample size in qualitative research by offering empirical evidence around justification practices associated with sample size. We next review the existing conceptual and empirical literature on sample size determination.

Sample size in qualitative research: Conceptual developments and empirical investigations

Qualitative research experts argue that there is no straightforward answer to the question of ‘how many’ and that sample size is contingent on a number of factors relating to epistemological, methodological and practical issues [ 36 ]. Sandelowski [ 4 ] recommends that qualitative sample sizes are large enough to allow the unfolding of a ‘new and richly textured understanding’ of the phenomenon under study, but small enough so that the ‘deep, case-oriented analysis’ (p. 183) of qualitative data is not precluded. Morse [ 11 ] posits that the more useable data are collected from each person, the fewer participants are needed. She invites researchers to take into account parameters, such as the scope of study, the nature of topic (i.e. complexity, accessibility), the quality of data, and the study design. Indeed, the level of structure of questions in qualitative interviewing has been found to influence the richness of data generated [ 37 ], and so, requires attention; empirical research shows that open questions, which are asked later on in the interview, tend to produce richer data [ 37 ].

Beyond such guidance, specific numerical recommendations have also been proffered, often based on experts’ experience of qualitative research. For example, Green and Thorogood [ 38 ] maintain that the experience of most qualitative researchers conducting an interview-based study with a fairly specific research question is that little new information is generated after interviewing 20 people or so belonging to one analytically relevant participant ‘category’ (pp. 102–104). Ritchie et al. [ 39 ] suggest that studies employing individual interviews conduct no more than 50 interviews so that researchers are able to manage the complexity of the analytic task. Similarly, Britten [ 40 ] notes that large interview studies will often comprise of 50 to 60 people. Experts have also offered numerical guidelines tailored to different theoretical and methodological traditions and specific research approaches, e.g. grounded theory, phenomenology [ 11 , 41 ]. More recently, a quantitative tool was proposed [ 42 ] to support a priori sample size determination based on estimates of the prevalence of themes in the population. Nevertheless, this more formulaic approach raised criticisms relating to assumptions about the conceptual [ 43 ] and ontological status of ‘themes’ [ 44 ] and the linearity ascribed to the processes of sampling, data collection and data analysis [ 45 ].

In terms of principles, Lincoln and Guba [ 17 ] proposed that sample size determination be guided by the criterion of informational redundancy , that is, sampling can be terminated when no new information is elicited by sampling more units. Following the logic of informational comprehensiveness Malterud et al. [ 18 ] introduced the concept of information power as a pragmatic guiding principle, suggesting that the more information power the sample provides, the smaller the sample size needs to be, and vice versa.

Undoubtedly, the most widely used principle for determining sample size and evaluating its sufficiency is that of saturation . The notion of saturation originates in grounded theory [ 15 ] – a qualitative methodological approach explicitly concerned with empirically-derived theory development – and is inextricably linked to theoretical sampling. Theoretical sampling describes an iterative process of data collection, data analysis and theory development whereby data collection is governed by emerging theory rather than predefined characteristics of the population. Grounded theory saturation (often called theoretical saturation) concerns the theoretical categories – as opposed to data – that are being developed and becomes evident when ‘gathering fresh data no longer sparks new theoretical insights, nor reveals new properties of your core theoretical categories’ [ 46 p. 113]. Saturation in grounded theory, therefore, does not equate to the more common focus on data repetition and moves beyond a singular focus on sample size as the justification of sampling adequacy [ 46 , 47 ]. Sample size in grounded theory cannot be determined a priori as it is contingent on the evolving theoretical categories.

Saturation – often under the terms of ‘data’ or ‘thematic’ saturation – has diffused into several qualitative communities beyond its origins in grounded theory. Alongside the expansion of its meaning, being variously equated with ‘no new data’, ‘no new themes’, and ‘no new codes’, saturation has emerged as the ‘gold standard’ in qualitative inquiry [ 2 , 26 ]. Nevertheless, and as Morse [ 48 ] asserts, whilst saturation is the most frequently invoked ‘guarantee of qualitative rigor’, ‘it is the one we know least about’ (p. 587). Certainly researchers caution that saturation is less applicable to, or appropriate for, particular types of qualitative research (e.g. conversation analysis, [ 49 ]; phenomenological research, [ 50 ]) whilst others reject the concept altogether [ 19 , 51 ].

Methodological studies in this area aim to provide guidance about saturation and develop a practical application of processes that ‘operationalise’ and evidence saturation. Guest, Bunce, and Johnson [ 26 ] analysed 60 interviews and found that saturation of themes was reached by the twelfth interview. They noted that their sample was relatively homogeneous, their research aims focused, so studies of more heterogeneous samples and with a broader scope would be likely to need a larger size to achieve saturation. Extending the enquiry to multi-site, cross-cultural research, Hagaman and Wutich [ 28 ] showed that sample sizes of 20 to 40 interviews were required to achieve data saturation of meta-themes that cut across research sites. In a theory-driven content analysis, Francis et al. [ 25 ] reached data saturation at the 17th interview for all their pre-determined theoretical constructs. The authors further proposed two main principles upon which specification of saturation be based: (a) researchers should a priori specify an initial analysis sample (e.g. 10 interviews) which will be used for the first round of analysis and (b) a stopping criterion , that is, a number of interviews (e.g. 3) that needs to be further conducted, the analysis of which will not yield any new themes or ideas. For greater transparency, Francis et al. [ 25 ] recommend that researchers present cumulative frequency graphs supporting their judgment that saturation was achieved. A comparative method for themes saturation (CoMeTS) has also been suggested [ 23 ] whereby the findings of each new interview are compared with those that have already emerged and if it does not yield any new theme, the ‘saturated terrain’ is assumed to have been established. Because the order in which interviews are analysed can influence saturation thresholds depending on the richness of the data, Constantinou et al. [ 23 ] recommend reordering and re-analysing interviews to confirm saturation. Hennink, Kaiser and Marconi’s [ 29 ] methodological study sheds further light on the problem of specifying and demonstrating saturation. Their analysis of interview data showed that code saturation (i.e. the point at which no additional issues are identified) was achieved at 9 interviews, but meaning saturation (i.e. the point at which no further dimensions, nuances, or insights of issues are identified) required 16–24 interviews. Although breadth can be achieved relatively soon, especially for high-prevalence and concrete codes, depth requires additional data, especially for codes of a more conceptual nature.

Critiquing the concept of saturation, Nelson [ 19 ] proposes five conceptual depth criteria in grounded theory projects to assess the robustness of the developing theory: (a) theoretical concepts should be supported by a wide range of evidence drawn from the data; (b) be demonstrably part of a network of inter-connected concepts; (c) demonstrate subtlety; (d) resonate with existing literature; and (e) can be successfully submitted to tests of external validity.

Other work has sought to examine practices of sample size reporting and sufficiency assessment across a range of disciplinary fields and research domains, from nutrition [ 34 ] and health education [ 32 ], to education and the health sciences [ 22 , 27 ], information systems [ 30 ], organisation and workplace studies [ 33 ], human computer interaction [ 21 ], and accounting studies [ 24 ]. Others investigated PhD qualitative studies [ 31 ] and grounded theory studies [ 35 ]. Incomplete and imprecise sample size reporting is commonly pinpointed by these investigations whilst assessment and justifications of sample size sufficiency are even more sporadic.

Sobal [ 34 ] examined the sample size of qualitative studies published in the Journal of Nutrition Education over a period of 30 years. Studies that employed individual interviews ( n  = 30) had an average sample size of 45 individuals and none of these explicitly reported whether their sample size sought and/or attained saturation. A minority of articles discussed how sample-related limitations (with the latter most often concerning the type of sample, rather than the size) limited generalizability. A further systematic analysis [ 32 ] of health education research over 20 years demonstrated that interview-based studies averaged 104 participants (range 2 to 720 interviewees). However, 40% did not report the number of participants. An examination of 83 qualitative interview studies in leading information systems journals [ 30 ] indicated little defence of sample sizes on the basis of recommendations by qualitative methodologists, prior relevant work, or the criterion of saturation. Rather, sample size seemed to correlate with factors such as the journal of publication or the region of study (US vs Europe vs Asia). These results led the authors to call for more rigor in determining and reporting sample size in qualitative information systems research and to recommend optimal sample size ranges for grounded theory (i.e. 20–30 interviews) and single case (i.e. 15–30 interviews) projects.

Similarly, fewer than 10% of articles in organisation and workplace studies provided a sample size justification relating to existing recommendations by methodologists, prior relevant work, or saturation [ 33 ], whilst only 17% of focus groups studies in health-related journals provided an explanation of sample size (i.e. number of focus groups), with saturation being the most frequently invoked argument, followed by published sample size recommendations and practical reasons [ 22 ]. The notion of saturation was also invoked by 11 out of the 51 most highly cited studies that Guetterman [ 27 ] reviewed in the fields of education and health sciences, of which six were grounded theory studies, four phenomenological and one a narrative inquiry. Finally, analysing 641 interview-based articles in accounting, Dai et al. [ 24 ] called for more rigor since a significant minority of studies did not report precise sample size.

Despite increasing attention to rigor in qualitative research (e.g. [ 52 ]) and more extensive methodological and analytical disclosures that seek to validate qualitative work [ 24 ], sample size reporting and sufficiency assessment remain inconsistent and partial, if not absent, across a range of research domains.

Objectives of the present study

The present study sought to enrich existing systematic analyses of the customs and practices of sample size reporting and justification by focusing on qualitative research relating to health. Additionally, this study attempted to expand previous empirical investigations by examining how qualitative sample sizes are characterised and discussed in academic narratives. Qualitative health research is an inter-disciplinary field that due to its affiliation with medical sciences, often faces views and positions reflective of a quantitative ethos. Thus qualitative health research constitutes an emblematic case that may help to unfold underlying philosophical and methodological differences across the scientific community that are crystallised in considerations of sample size. The present research, therefore, incorporates a comparative element on the basis of three different disciplines engaging with qualitative health research: medicine, psychology, and sociology. We chose to focus our analysis on single-per-participant-interview designs as this not only presents a popular and widespread methodological choice in qualitative health research, but also as the method where consideration of sample size – defined as the number of interviewees – is particularly salient.

Study design

A structured search for articles reporting cross-sectional, interview-based qualitative studies was carried out and eligible reports were systematically reviewed and analysed employing both quantitative and qualitative analytic techniques.

We selected journals which (a) follow a peer review process, (b) are considered high quality and influential in their field as reflected in journal metrics, and (c) are receptive to, and publish, qualitative research (Additional File  1 presents the journals’ editorial positions in relation to qualitative research and sample considerations where available). Three health-related journals were chosen, each representing a different disciplinary field; the British Medical Journal (BMJ) representing medicine, the British Journal of Health Psychology (BJHP) representing psychology, and the Sociology of Health & Illness (SHI) representing sociology.

Search strategy to identify studies

Employing the search function of each individual journal, we used the terms ‘interview*’ AND ‘qualitative’ and limited the results to articles published between 1 January 2003 and 22 September 2017 (i.e. a 15-year review period).

Eligibility criteria

To be eligible for inclusion in the review, the article had to report a cross-sectional study design. Longitudinal studies were thus excluded whilst studies conducted within a broader research programme (e.g. interview studies nested in a trial, as part of a broader ethnography, as part of a longitudinal research) were included if they reported only single-time qualitative interviews. The method of data collection had to be individual, synchronous qualitative interviews (i.e. group interviews, structured interviews and e-mail interviews over a period of time were excluded), and the data had to be analysed qualitatively (i.e. studies that quantified their qualitative data were excluded). Mixed method studies and articles reporting more than one qualitative method of data collection (e.g. individual interviews and focus groups) were excluded. Figure  1 , a PRISMA flow diagram [ 53 ], shows the number of: articles obtained from the searches and screened; papers assessed for eligibility; and articles included in the review (Additional File  2 provides the full list of articles included in the review and their unique identifying code – e.g. BMJ01, BJHP02, SHI03). One review author (KV) assessed the eligibility of all papers identified from the searches. When in doubt, discussions about retaining or excluding articles were held between KV and JB in regular meetings, and decisions were jointly made.

figure 1

PRISMA flow diagram

Data extraction and analysis

A data extraction form was developed (see Additional File  3 ) recording three areas of information: (a) information about the article (e.g. authors, title, journal, year of publication etc.); (b) information about the aims of the study, the sample size and any justification for this, the participant characteristics, the sampling technique and any sample-related observations or comments made by the authors; and (c) information about the method or technique(s) of data analysis, the number of researchers involved in the analysis, the potential use of software, and any discussion around epistemological considerations. The Abstract, Methods and Discussion (and/or Conclusion) sections of each article were examined by one author (KV) who extracted all the relevant information. This was directly copied from the articles and, when appropriate, comments, notes and initial thoughts were written down.

To examine the kinds of sample size justifications provided by articles, an inductive content analysis [ 54 ] was initially conducted. On the basis of this analysis, the categories that expressed qualitatively different sample size justifications were developed.

We also extracted or coded quantitative data regarding the following aspects:

Journal and year of publication

Number of interviews

Number of participants

Presence of sample size justification(s) (Yes/No)

Presence of a particular sample size justification category (Yes/No), and

Number of sample size justifications provided

Descriptive and inferential statistical analyses were used to explore these data.

A thematic analysis [ 55 ] was then performed on all scientific narratives that discussed or commented on the sample size of the study. These narratives were evident both in papers that justified their sample size and those that did not. To identify these narratives, in addition to the methods sections, the discussion sections of the reviewed articles were also examined and relevant data were extracted and analysed.

In total, 214 articles – 21 in the BMJ, 53 in the BJHP and 140 in the SHI – were eligible for inclusion in the review. Table  1 provides basic information about the sample sizes – measured in number of interviews – of the studies reviewed across the three journals. Figure  2 depicts the number of eligible articles published each year per journal.

figure 2

The publication of qualitative studies in the BMJ was significantly reduced from 2012 onwards and this appears to coincide with the initiation of the BMJ Open to which qualitative studies were possibly directed.

Pairwise comparisons following a significant Kruskal-Wallis Footnote 2 test indicated that the studies published in the BJHP had significantly ( p  < .001) smaller samples sizes than those published either in the BMJ or the SHI. Sample sizes of BMJ and SHI articles did not differ significantly from each other.

Sample size justifications: Results from the quantitative and qualitative content analysis

Ten (47.6%) of the 21 BMJ studies, 26 (49.1%) of the 53 BJHP papers and 24 (17.1%) of the 140 SHI articles provided some sort of sample size justification. As shown in Table  2 , the majority of articles which justified their sample size provided one justification (70% of articles); fourteen studies (25%) provided two distinct justifications; one study (1.7%) gave three justifications and two studies (3.3%) expressed four distinct justifications.

There was no association between the number of interviews (i.e. sample size) conducted and the provision of a justification (rpb = .054, p  = .433). Within journals, Mann-Whitney tests indicated that sample sizes of ‘justifying’ and ‘non-justifying’ articles in the BMJ and SHI did not differ significantly from each other. In the BJHP, ‘justifying’ articles ( Mean rank  = 31.3) had significantly larger sample sizes than ‘non-justifying’ studies ( Mean rank  = 22.7; U = 237.000, p  < .05).

There was a significant association between the journal a paper was published in and the provision of a justification (χ 2 (2) = 23.83, p  < .001). BJHP studies provided a sample size justification significantly more often than would be expected ( z  = 2.9); SHI studies significantly less often ( z  = − 2.4). If an article was published in the BJHP, the odds of providing a justification were 4.8 times higher than if published in the SHI. Similarly if published in the BMJ, the odds of a study justifying its sample size were 4.5 times higher than in the SHI.

The qualitative content analysis of the scientific narratives identified eleven different sample size justifications. These are described below and illustrated with excerpts from relevant articles. By way of a summary, the frequency with which these were deployed across the three journals is indicated in Table  3 .

Saturation was the most commonly invoked principle (55.4% of all justifications) deployed by studies across all three journals to justify the sufficiency of their sample size. In the BMJ, two studies claimed that they achieved data saturation (BMJ17; BMJ18) and one article referred descriptively to achieving saturation without explicitly using the term (BMJ13). Interestingly, BMJ13 included data in the analysis beyond the point of saturation in search of ‘unusual/deviant observations’ and with a view to establishing findings consistency.

Thirty three women were approached to take part in the interview study. Twenty seven agreed and 21 (aged 21–64, median 40) were interviewed before data saturation was reached (one tape failure meant that 20 interviews were available for analysis). (BMJ17). No new topics were identified following analysis of approximately two thirds of the interviews; however, all interviews were coded in order to develop a better understanding of how characteristic the views and reported behaviours were, and also to collect further examples of unusual/deviant observations. (BMJ13).

Two articles reported pre-determining their sample size with a view to achieving data saturation (BMJ08 – see extract in section In line with existing research ; BMJ15 – see extract in section Pragmatic considerations ) without further specifying if this was achieved. One paper claimed theoretical saturation (BMJ06) conceived as being when “no further recurring themes emerging from the analysis” whilst another study argued that although the analytic categories were highly saturated, it was not possible to determine whether theoretical saturation had been achieved (BMJ04). One article (BMJ18) cited a reference to support its position on saturation.

In the BJHP, six articles claimed that they achieved data saturation (BJHP21; BJHP32; BJHP39; BJHP48; BJHP49; BJHP52) and one article stated that, given their sample size and the guidelines for achieving data saturation, it anticipated that saturation would be attained (BJHP50).

Recruitment continued until data saturation was reached, defined as the point at which no new themes emerged. (BJHP48). It has previously been recommended that qualitative studies require a minimum sample size of at least 12 to reach data saturation (Clarke & Braun, 2013; Fugard & Potts, 2014; Guest, Bunce, & Johnson, 2006) Therefore, a sample of 13 was deemed sufficient for the qualitative analysis and scale of this study. (BJHP50).

Two studies argued that they achieved thematic saturation (BJHP28 – see extract in section Sample size guidelines ; BJHP31) and one (BJHP30) article, explicitly concerned with theory development and deploying theoretical sampling, claimed both theoretical and data saturation.

The final sample size was determined by thematic saturation, the point at which new data appears to no longer contribute to the findings due to repetition of themes and comments by participants (Morse, 1995). At this point, data generation was terminated. (BJHP31).

Five studies argued that they achieved (BJHP05; BJHP33; BJHP40; BJHP13 – see extract in section Pragmatic considerations ) or anticipated (BJHP46) saturation without any further specification of the term. BJHP17 referred descriptively to a state of achieved saturation without specifically using the term. Saturation of coding , but not saturation of themes, was claimed to have been reached by one article (BJHP18). Two articles explicitly stated that they did not achieve saturation; instead claiming a level of theme completeness (BJHP27) or that themes being replicated (BJHP53) were arguments for sufficiency of their sample size.

Furthermore, data collection ceased on pragmatic grounds rather than at the point when saturation point was reached. Despite this, although nuances within sub-themes were still emerging towards the end of data analysis, the themes themselves were being replicated indicating a level of completeness. (BJHP27).

Finally, one article criticised and explicitly renounced the notion of data saturation claiming that, on the contrary, the criterion of theoretical sufficiency determined its sample size (BJHP16).

According to the original Grounded Theory texts, data collection should continue until there are no new discoveries ( i.e. , ‘data saturation’; Glaser & Strauss, 1967). However, recent revisions of this process have discussed how it is rare that data collection is an exhaustive process and researchers should rely on how well their data are able to create a sufficient theoretical account or ‘theoretical sufficiency’ (Dey, 1999). For this study, it was decided that theoretical sufficiency would guide recruitment, rather than looking for data saturation. (BJHP16).

Ten out of the 20 BJHP articles that employed the argument of saturation used one or more citations relating to this principle.

In the SHI, one article (SHI01) claimed that it achieved category saturation based on authors’ judgment.

This number was not fixed in advance, but was guided by the sampling strategy and the judgement, based on the analysis of the data, of the point at which ‘category saturation’ was achieved. (SHI01).

Three articles described a state of achieved saturation without using the term or specifying what sort of saturation they had achieved (i.e. data, theoretical, thematic saturation) (SHI04; SHI13; SHI30) whilst another four articles explicitly stated that they achieved saturation (SHI100; SHI125; SHI136; SHI137). Two papers stated that they achieved data saturation (SHI73 – see extract in section Sample size guidelines ; SHI113), two claimed theoretical saturation (SHI78; SHI115) and two referred to achieving thematic saturation (SHI87; SHI139) or to saturated themes (SHI29; SHI50).

Recruitment and analysis ceased once theoretical saturation was reached in the categories described below (Lincoln and Guba 1985). (SHI115). The respondents’ quotes drawn on below were chosen as representative, and illustrate saturated themes. (SHI50).

One article stated that thematic saturation was anticipated with its sample size (SHI94). Briefly referring to the difficulty in pinpointing achievement of theoretical saturation, SHI32 (see extract in section Richness and volume of data ) defended the sufficiency of its sample size on the basis of “the high degree of consensus [that] had begun to emerge among those interviewed”, suggesting that information from interviews was being replicated. Finally, SHI112 (see extract in section Further sampling to check findings consistency ) argued that it achieved saturation of discursive patterns . Seven of the 19 SHI articles cited references to support their position on saturation (see Additional File  4 for the full list of citations used by articles to support their position on saturation across the three journals).

Overall, it is clear that the concept of saturation encompassed a wide range of variants expressed in terms such as saturation, data saturation, thematic saturation, theoretical saturation, category saturation, saturation of coding, saturation of discursive themes, theme completeness. It is noteworthy, however, that although these various claims were sometimes supported with reference to the literature, they were not evidenced in relation to the study at hand.

Pragmatic considerations

The determination of sample size on the basis of pragmatic considerations was the second most frequently invoked argument (9.6% of all justifications) appearing in all three journals. In the BMJ, one article (BMJ15) appealed to pragmatic reasons, relating to time constraints and the difficulty to access certain study populations, to justify the determination of its sample size.

On the basis of the researchers’ previous experience and the literature, [30, 31] we estimated that recruitment of 15–20 patients at each site would achieve data saturation when data from each site were analysed separately. We set a target of seven to 10 caregivers per site because of time constraints and the anticipated difficulty of accessing caregivers at some home based care services. This gave a target sample of 75–100 patients and 35–50 caregivers overall. (BMJ15).

In the BJHP, four articles mentioned pragmatic considerations relating to time or financial constraints (BJHP27 – see extract in section Saturation ; BJHP53), the participant response rate (BJHP13), and the fixed (and thus limited) size of the participant pool from which interviewees were sampled (BJHP18).

We had aimed to continue interviewing until we had reached saturation, a point whereby further data collection would yield no further themes. In practice, the number of individuals volunteering to participate dictated when recruitment into the study ceased (15 young people, 15 parents). Nonetheless, by the last few interviews, significant repetition of concepts was occurring, suggesting ample sampling. (BJHP13).

Finally, three SHI articles explained their sample size with reference to practical aspects: time constraints and project manageability (SHI56), limited availability of respondents and project resources (SHI131), and time constraints (SHI113).

The size of the sample was largely determined by the availability of respondents and resources to complete the study. Its composition reflected, as far as practicable, our interest in how contextual factors (for example, gender relations and ethnicity) mediated the illness experience. (SHI131).

Qualities of the analysis

This sample size justification (8.4% of all justifications) was mainly employed by BJHP articles and referred to an intensive, idiographic and/or latently focused analysis, i.e. that moved beyond description. More specifically, six articles defended their sample size on the basis of an intensive analysis of transcripts and/or the idiographic focus of the study/analysis. Four of these papers (BJHP02; BJHP19; BJHP24; BJHP47) adopted an Interpretative Phenomenological Analysis (IPA) approach.

The current study employed a sample of 10 in keeping with the aim of exploring each participant’s account (Smith et al. , 1999). (BJHP19).

BJHP47 explicitly renounced the notion of saturation within an IPA approach. The other two BJHP articles conducted thematic analysis (BJHP34; BJHP38). The level of analysis – i.e. latent as opposed to a more superficial descriptive analysis – was also invoked as a justification by BJHP38 alongside the argument of an intensive analysis of individual transcripts

The resulting sample size was at the lower end of the range of sample sizes employed in thematic analysis (Braun & Clarke, 2013). This was in order to enable significant reflection, dialogue, and time on each transcript and was in line with the more latent level of analysis employed, to identify underlying ideas, rather than a more superficial descriptive analysis (Braun & Clarke, 2006). (BJHP38).

Finally, one BMJ paper (BMJ21) defended its sample size with reference to the complexity of the analytic task.

We stopped recruitment when we reached 30–35 interviews, owing to the depth and duration of interviews, richness of data, and complexity of the analytical task. (BMJ21).

Meet sampling requirements

Meeting sampling requirements (7.2% of all justifications) was another argument employed by two BMJ and four SHI articles to explain their sample size. Achieving maximum variation sampling in terms of specific interviewee characteristics determined and explained the sample size of two BMJ studies (BMJ02; BMJ16 – see extract in section Meet research design requirements ).

Recruitment continued until sampling frame requirements were met for diversity in age, sex, ethnicity, frequency of attendance, and health status. (BMJ02).

Regarding the SHI articles, two papers explained their numbers on the basis of their sampling strategy (SHI01- see extract in section Saturation ; SHI23) whilst sampling requirements that would help attain sample heterogeneity in terms of a particular characteristic of interest was cited by one paper (SHI127).

The combination of matching the recruitment sites for the quantitative research and the additional purposive criteria led to 104 phase 2 interviews (Internet (OLC): 21; Internet (FTF): 20); Gyms (FTF): 23; HIV testing (FTF): 20; HIV treatment (FTF): 20.) (SHI23). Of the fifty interviews conducted, thirty were translated from Spanish into English. These thirty, from which we draw our findings, were chosen for translation based on heterogeneity in depressive symptomology and educational attainment. (SHI127).

Finally, the pre-determination of sample size on the basis of sampling requirements was stated by one article though this was not used to justify the number of interviews (SHI10).

Sample size guidelines

Five BJHP articles (BJHP28; BJHP38 – see extract in section Qualities of the analysis ; BJHP46; BJHP47; BJHP50 – see extract in section Saturation ) and one SHI paper (SHI73) relied on citing existing sample size guidelines or norms within research traditions to determine and subsequently defend their sample size (7.2% of all justifications).

Sample size guidelines suggested a range between 20 and 30 interviews to be adequate (Creswell, 1998). Interviewer and note taker agreed that thematic saturation, the point at which no new concepts emerge from subsequent interviews (Patton, 2002), was achieved following completion of 20 interviews. (BJHP28). Interviewing continued until we deemed data saturation to have been reached (the point at which no new themes were emerging). Researchers have proposed 30 as an approximate or working number of interviews at which one could expect to be reaching theoretical saturation when using a semi-structured interview approach (Morse 2000), although this can vary depending on the heterogeneity of respondents interviewed and complexity of the issues explored. (SHI73).

In line with existing research

Sample sizes of published literature in the area of the subject matter under investigation (3.5% of all justifications) were used by 2 BMJ articles as guidance and a precedent for determining and defending their own sample size (BMJ08; BMJ15 – see extract in section Pragmatic considerations ).

We drew participants from a list of prisoners who were scheduled for release each week, sampling them until we reached the target of 35 cases, with a view to achieving data saturation within the scope of the study and sufficient follow-up interviews and in line with recent studies [8–10]. (BMJ08).

Similarly, BJHP38 (see extract in section Qualities of the analysis ) claimed that its sample size was within the range of sample sizes of published studies that use its analytic approach.

Richness and volume of data

BMJ21 (see extract in section Qualities of the analysis ) and SHI32 referred to the richness, detailed nature, and volume of data collected (2.3% of all justifications) to justify the sufficiency of their sample size.

Although there were more potential interviewees from those contacted by postcode selection, it was decided to stop recruitment after the 10th interview and focus on analysis of this sample. The material collected was considerable and, given the focused nature of the study, extremely detailed. Moreover, a high degree of consensus had begun to emerge among those interviewed, and while it is always difficult to judge at what point ‘theoretical saturation’ has been reached, or how many interviews would be required to uncover exception(s), it was felt the number was sufficient to satisfy the aims of this small in-depth investigation (Strauss and Corbin 1990). (SHI32).

Meet research design requirements

Determination of sample size so that it is in line with, and serves the requirements of, the research design (2.3% of all justifications) that the study adopted was another justification used by 2 BMJ papers (BMJ16; BMJ08 – see extract in section In line with existing research ).

We aimed for diverse, maximum variation samples [20] totalling 80 respondents from different social backgrounds and ethnic groups and those bereaved due to different types of suicide and traumatic death. We could have interviewed a smaller sample at different points in time (a qualitative longitudinal study) but chose instead to seek a broad range of experiences by interviewing those bereaved many years ago and others bereaved more recently; those bereaved in different circumstances and with different relations to the deceased; and people who lived in different parts of the UK; with different support systems and coroners’ procedures (see Tables 1 and 2 for more details). (BMJ16).

Researchers’ previous experience

The researchers’ previous experience (possibly referring to experience with qualitative research) was invoked by BMJ15 (see extract in section Pragmatic considerations ) as a justification for the determination of sample size.

Nature of study

One BJHP paper argued that the sample size was appropriate for the exploratory nature of the study (BJHP38).

A sample of eight participants was deemed appropriate because of the exploratory nature of this research and the focus on identifying underlying ideas about the topic. (BJHP38).

Further sampling to check findings consistency

Finally, SHI112 argued that once it had achieved saturation of discursive patterns, further sampling was decided and conducted to check for consistency of the findings.

Within each of the age-stratified groups, interviews were randomly sampled until saturation of discursive patterns was achieved. This resulted in a sample of 67 interviews. Once this sample had been analysed, one further interview from each age-stratified group was randomly chosen to check for consistency of the findings. Using this approach it was possible to more carefully explore children’s discourse about the ‘I’, agency, relationality and power in the thematic areas, revealing the subtle discursive variations described in this article. (SHI112).

Thematic analysis of passages discussing sample size

This analysis resulted in two overarching thematic areas; the first concerned the variation in the characterisation of sample size sufficiency, and the second related to the perceived threats deriving from sample size insufficiency.

Characterisations of sample size sufficiency

The analysis showed that there were three main characterisations of the sample size in the articles that provided relevant comments and discussion: (a) the vast majority of these qualitative studies ( n  = 42) considered their sample size as ‘small’ and this was seen and discussed as a limitation; only two articles viewed their small sample size as desirable and appropriate (b) a minority of articles ( n  = 4) proclaimed that their achieved sample size was ‘sufficient’; and (c) finally, a small group of studies ( n  = 5) characterised their sample size as ‘large’. Whilst achieving a ‘large’ sample size was sometimes viewed positively because it led to richer results, there were also occasions when a large sample size was problematic rather than desirable.

‘Small’ but why and for whom?

A number of articles which characterised their sample size as ‘small’ did so against an implicit or explicit quantitative framework of reference. Interestingly, three studies that claimed to have achieved data saturation or ‘theoretical sufficiency’ with their sample size, discussed or noted as a limitation in their discussion their ‘small’ sample size, raising the question of why, or for whom, the sample size was considered small given that the qualitative criterion of saturation had been satisfied.

The current study has a number of limitations. The sample size was small (n = 11) and, however, large enough for no new themes to emerge. (BJHP39). The study has two principal limitations. The first of these relates to the small number of respondents who took part in the study. (SHI73).

Other articles appeared to accept and acknowledge that their sample was flawed because of its small size (as well as other compositional ‘deficits’ e.g. non-representativeness, biases, self-selection) or anticipated that they might be criticized for their small sample size. It seemed that the imagined audience – perhaps reviewer or reader – was one inclined to hold the tenets of quantitative research, and certainly one to whom it was important to indicate the recognition that small samples were likely to be problematic. That one’s sample might be thought small was often construed as a limitation couched in a discourse of regret or apology.

Very occasionally, the articulation of the small size as a limitation was explicitly aligned against an espoused positivist framework and quantitative research.

This study has some limitations. Firstly, the 100 incidents sample represents a small number of the total number of serious incidents that occurs every year. 26 We sent out a nationwide invitation and do not know why more people did not volunteer for the study. Our lack of epidemiological knowledge about healthcare incidents, however, means that determining an appropriate sample size continues to be difficult. (BMJ20).

Indicative of an apparent oscillation of qualitative researchers between the different requirements and protocols demarcating the quantitative and qualitative worlds, there were a few instances of articles which briefly recognised their ‘small’ sample size as a limitation, but then defended their study on more qualitative grounds, such as their ability and success at capturing the complexity of experience and delving into the idiographic, and at generating particularly rich data.

This research, while limited in size, has sought to capture some of the complexity attached to men’s attitudes and experiences concerning incomes and material circumstances. (SHI35). Our numbers are small because negotiating access to social networks was slow and labour intensive, but our methods generated exceptionally rich data. (BMJ21). This study could be criticised for using a small and unrepresentative sample. Given that older adults have been ignored in the research concerning suntanning, fair-skinned older adults are the most likely to experience skin cancer, and women privilege appearance over health when it comes to sunbathing practices, our study offers depth and richness of data in a demographic group much in need of research attention. (SHI57).

‘Good enough’ sample sizes

Only four articles expressed some degree of confidence that their achieved sample size was sufficient. For example, SHI139, in line with the justification of thematic saturation that it offered, expressed trust in its sample size sufficiency despite the poor response rate. Similarly, BJHP04, which did not provide a sample size justification, argued that it targeted a larger sample size in order to eventually recruit a sufficient number of interviewees, due to anticipated low response rate.

Twenty-three people with type I diabetes from the target population of 133 ( i.e. 17.3%) consented to participate but four did not then respond to further contacts (total N = 19). The relatively low response rate was anticipated, due to the busy life-styles of young people in the age range, the geographical constraints, and the time required to participate in a semi-structured interview, so a larger target sample allowed a sufficient number of participants to be recruited. (BJHP04).

Two other articles (BJHP35; SHI32) linked the claimed sufficiency to the scope (i.e. ‘small, in-depth investigation’), aims and nature (i.e. ‘exploratory’) of their studies, thus anchoring their numbers to the particular context of their research. Nevertheless, claims of sample size sufficiency were sometimes undermined when they were juxtaposed with an acknowledgement that a larger sample size would be more scientifically productive.

Although our sample size was sufficient for this exploratory study, a more diverse sample including participants with lower socioeconomic status and more ethnic variation would be informative. A larger sample could also ensure inclusion of a more representative range of apps operating on a wider range of platforms. (BJHP35).

‘Large’ sample sizes - Promise or peril?

Three articles (BMJ13; BJHP05; BJHP48) which all provided the justification of saturation, characterised their sample size as ‘large’ and narrated this oversufficiency in positive terms as it allowed richer data and findings and enhanced the potential for generalisation. The type of generalisation aspired to (BJHP48) was not further specified however.

This study used rich data provided by a relatively large sample of expert informants on an important but under-researched topic. (BMJ13). Qualitative research provides a unique opportunity to understand a clinical problem from the patient’s perspective. This study had a large diverse sample, recruited through a range of locations and used in-depth interviews which enhance the richness and generalizability of the results. (BJHP48).

And whilst a ‘large’ sample size was endorsed and valued by some qualitative researchers, within the psychological tradition of IPA, a ‘large’ sample size was counter-normative and therefore needed to be justified. Four BJHP studies, all adopting IPA, expressed the appropriateness or desirability of ‘small’ sample sizes (BJHP41; BJHP45) or hastened to explain why they included a larger than typical sample size (BJHP32; BJHP47). For example, BJHP32 below provides a rationale for how an IPA study can accommodate a large sample size and how this was indeed suitable for the purposes of the particular research. To strengthen the explanation for choosing a non-normative sample size, previous IPA research citing a similar sample size approach is used as a precedent.

Small scale IPA studies allow in-depth analysis which would not be possible with larger samples (Smith et al. , 2009). (BJHP41). Although IPA generally involves intense scrutiny of a small number of transcripts, it was decided to recruit a larger diverse sample as this is the first qualitative study of this population in the United Kingdom (as far as we know) and we wanted to gain an overview. Indeed, Smith, Flowers, and Larkin (2009) agree that IPA is suitable for larger groups. However, the emphasis changes from an in-depth individualistic analysis to one in which common themes from shared experiences of a group of people can be elicited and used to understand the network of relationships between themes that emerge from the interviews. This large-scale format of IPA has been used by other researchers in the field of false-positive research. Baillie, Smith, Hewison, and Mason (2000) conducted an IPA study, with 24 participants, of ultrasound screening for chromosomal abnormality; they found that this larger number of participants enabled them to produce a more refined and cohesive account. (BJHP32).

The IPA articles found in the BJHP were the only instances where a ‘small’ sample size was advocated and a ‘large’ sample size problematized and defended. These IPA studies illustrate that the characterisation of sample size sufficiency can be a function of researchers’ theoretical and epistemological commitments rather than the result of an ‘objective’ sample size assessment.

Threats from sample size insufficiency

As shown above, the majority of articles that commented on their sample size, simultaneously characterized it as small and problematic. On those occasions that authors did not simply cite their ‘small’ sample size as a study limitation but rather continued and provided an account of how and why a small sample size was problematic, two important scientific qualities of the research seemed to be threatened: the generalizability and validity of results.

Generalizability

Those who characterised their sample as ‘small’ connected this to the limited potential for generalization of the results. Other features related to the sample – often some kind of compositional particularity – were also linked to limited potential for generalisation. Though not always explicitly articulated to what form of generalisation the articles referred to (see BJHP09), generalisation was mostly conceived in nomothetic terms, that is, it concerned the potential to draw inferences from the sample to the broader study population (‘representational generalisation’ – see BJHP31) and less often to other populations or cultures.

It must be noted that samples are small and whilst in both groups the majority of those women eligible participated, generalizability cannot be assumed. (BJHP09). The study’s limitations should be acknowledged: Data are presented from interviews with a relatively small group of participants, and thus, the views are not necessarily generalizable to all patients and clinicians. In particular, patients were only recruited from secondary care services where COFP diagnoses are typically confirmed. The sample therefore is unlikely to represent the full spectrum of patients, particularly those who are not referred to, or who have been discharged from dental services. (BJHP31).

Without explicitly using the term generalisation, two SHI articles noted how their ‘small’ sample size imposed limits on ‘the extent that we can extrapolate from these participants’ accounts’ (SHI114) or to the possibility ‘to draw far-reaching conclusions from the results’ (SHI124).

Interestingly, only a minority of articles alluded to, or invoked, a type of generalisation that is aligned with qualitative research, that is, idiographic generalisation (i.e. generalisation that can be made from and about cases [ 5 ]). These articles, all published in the discipline of sociology, defended their findings in terms of the possibility of drawing logical and conceptual inferences to other contexts and of generating understanding that has the potential to advance knowledge, despite their ‘small’ size. One article (SHI139) clearly contrasted nomothetic (statistical) generalisation to idiographic generalisation, arguing that the lack of statistical generalizability does not nullify the ability of qualitative research to still be relevant beyond the sample studied.

Further, these data do not need to be statistically generalisable for us to draw inferences that may advance medicalisation analyses (Charmaz 2014). These data may be seen as an opportunity to generate further hypotheses and are a unique application of the medicalisation framework. (SHI139). Although a small-scale qualitative study related to school counselling, this analysis can be usefully regarded as a case study of the successful utilisation of mental health-related resources by adolescents. As many of the issues explored are of relevance to mental health stigma more generally, it may also provide insights into adult engagement in services. It shows how a sociological analysis, which uses positioning theory to examine how people negotiate, partially accept and simultaneously resist stigmatisation in relation to mental health concerns, can contribute to an elucidation of the social processes and narrative constructions which may maintain as well as bridge the mental health service gap. (SHI103).

Only one article (SHI30) used the term transferability to argue for the potential of wider relevance of the results which was thought to be more the product of the composition of the sample (i.e. diverse sample), rather than the sample size.

The second major concern that arose from a ‘small’ sample size pertained to the internal validity of findings (i.e. here the term is used to denote the ‘truth’ or credibility of research findings). Authors expressed uncertainty about the degree of confidence in particular aspects or patterns of their results, primarily those that concerned some form of differentiation on the basis of relevant participant characteristics.

The information source preferred seemed to vary according to parents’ education; however, the sample size is too small to draw conclusions about such patterns. (SHI80). Although our numbers were too small to demonstrate gender differences with any certainty, it does seem that the biomedical and erotic scripts may be more common in the accounts of men and the relational script more common in the accounts of women. (SHI81).

In other instances, articles expressed uncertainty about whether their results accounted for the full spectrum and variation of the phenomenon under investigation. In other words, a ‘small’ sample size (alongside compositional ‘deficits’ such as a not statistically representative sample) was seen to threaten the ‘content validity’ of the results which in turn led to constructions of the study conclusions as tentative.

Data collection ceased on pragmatic grounds rather than when no new information appeared to be obtained ( i.e. , saturation point). As such, care should be taken not to overstate the findings. Whilst the themes from the initial interviews seemed to be replicated in the later interviews, further interviews may have identified additional themes or provided more nuanced explanations. (BJHP53). …it should be acknowledged that this study was based on a small sample of self-selected couples in enduring marriages who were not broadly representative of the population. Thus, participants may not be representative of couples that experience postnatal PTSD. It is therefore unlikely that all the key themes have been identified and explored. For example, couples who were excluded from the study because the male partner declined to participate may have been experiencing greater interpersonal difficulties. (BJHP03).

In other instances, articles attempted to preserve a degree of credibility of their results, despite the recognition that the sample size was ‘small’. Clarity and sharpness of emerging themes and alignment with previous relevant work were the arguments employed to warrant the validity of the results.

This study focused on British Chinese carers of patients with affective disorders, using a qualitative methodology to synthesise the sociocultural representations of illness within this community. Despite the small sample size, clear themes emerged from the narratives that were sufficient for this exploratory investigation. (SHI98).

The present study sought to examine how qualitative sample sizes in health-related research are characterised and justified. In line with previous studies [ 22 , 30 , 33 , 34 ] the findings demonstrate that reporting of sample size sufficiency is limited; just over 50% of articles in the BMJ and BJHP and 82% in the SHI did not provide any sample size justification. Providing a sample size justification was not related to the number of interviews conducted, but it was associated with the journal that the article was published in, indicating the influence of disciplinary or publishing norms, also reported in prior research [ 30 ]. This lack of transparency about sample size sufficiency is problematic given that most qualitative researchers would agree that it is an important marker of quality [ 56 , 57 ]. Moreover, and with the rise of qualitative research in social sciences, efforts to synthesise existing evidence and assess its quality are obstructed by poor reporting [ 58 , 59 ].

When authors justified their sample size, our findings indicate that sufficiency was mostly appraised with reference to features that were intrinsic to the study, in agreement with general advice on sample size determination [ 4 , 11 , 36 ]. The principle of saturation was the most commonly invoked argument [ 22 ] accounting for 55% of all justifications. A wide range of variants of saturation was evident corroborating the proliferation of the meaning of the term [ 49 ] and reflecting different underlying conceptualisations or models of saturation [ 20 ]. Nevertheless, claims of saturation were never substantiated in relation to procedures conducted in the study itself, endorsing similar observations in the literature [ 25 , 30 , 47 ]. Claims of saturation were sometimes supported with citations of other literature, suggesting a removal of the concept away from the characteristics of the study at hand. Pragmatic considerations, such as resource constraints or participant response rate and availability, was the second most frequently used argument accounting for approximately 10% of justifications and another 23% of justifications also represented intrinsic-to-the-study characteristics (i.e. qualities of the analysis, meeting sampling or research design requirements, richness and volume of the data obtained, nature of study, further sampling to check findings consistency).

Only, 12% of mentions of sample size justification pertained to arguments that were external to the study at hand, in the form of existing sample size guidelines and prior research that sets precedents. Whilst community norms and prior research can establish useful rules of thumb for estimating sample sizes [ 60 ] – and reveal what sizes are more likely to be acceptable within research communities – researchers should avoid adopting these norms uncritically, especially when such guidelines [e.g. 30 , 35 ], might be based on research that does not provide adequate evidence of sample size sufficiency. Similarly, whilst methodological research that seeks to demonstrate the achievement of saturation is invaluable since it explicates the parameters upon which saturation is contingent and indicates when a research project is likely to require a smaller or a larger sample [e.g. 29 ], specific numbers at which saturation was achieved within these projects cannot be routinely extrapolated for other projects. We concur with existing views [ 11 , 36 ] that the consideration of the characteristics of the study at hand, such as the epistemological and theoretical approach, the nature of the phenomenon under investigation, the aims and scope of the study, the quality and richness of data, or the researcher’s experience and skills of conducting qualitative research, should be the primary guide in determining sample size and assessing its sufficiency.

Moreover, although numbers in qualitative research are not unimportant [ 61 ], sample size should not be considered alone but be embedded in the more encompassing examination of data adequacy [ 56 , 57 ]. Erickson’s [ 62 ] dimensions of ‘evidentiary adequacy’ are useful here. He explains the concept in terms of adequate amounts of evidence, adequate variety in kinds of evidence, adequate interpretive status of evidence, adequate disconfirming evidence, and adequate discrepant case analysis. All dimensions might not be relevant across all qualitative research designs, but this illustrates the thickness of the concept of data adequacy, taking it beyond sample size.

The present research also demonstrated that sample sizes were commonly seen as ‘small’ and insufficient and discussed as limitation. Often unjustified (and in two cases incongruent with their own claims of saturation) these findings imply that sample size in qualitative health research is often adversely judged (or expected to be judged) against an implicit, yet omnipresent, quasi-quantitative standpoint. Indeed there were a few instances in our data where authors appeared, possibly in response to reviewers, to resist to some sort of quantification of their results. This implicit reference point became more apparent when authors discussed the threats deriving from an insufficient sample size. Whilst the concerns about internal validity might be legitimate to the extent that qualitative research projects, which are broadly related to realism, are set to examine phenomena in sufficient breadth and depth, the concerns around generalizability revealed a conceptualisation that is not compatible with purposive sampling. The limited potential for generalisation, as a result of a small sample size, was often discussed in nomothetic, statistical terms. Only occasionally was analytic or idiographic generalisation invoked to warrant the value of the study’s findings [ 5 , 17 ].

Strengths and limitations of the present study

We note, first, the limited number of health-related journals reviewed, so that only a ‘snapshot’ of qualitative health research has been captured. Examining additional disciplines (e.g. nursing sciences) as well as inter-disciplinary journals would add to the findings of this analysis. Nevertheless, our study is the first to provide some comparative insights on the basis of disciplines that are differently attached to the legacy of positivism and analysed literature published over a lengthy period of time (15 years). Guetterman [ 27 ] also examined health-related literature but this analysis was restricted to 26 most highly cited articles published over a period of five years whilst Carlsen and Glenton’s [ 22 ] study concentrated on focus groups health research. Moreover, although it was our intention to examine sample size justification in relation to the epistemological and theoretical positions of articles, this proved to be challenging largely due to absence of relevant information, or the difficulty into discerning clearly articles’ positions [ 63 ] and classifying them under specific approaches (e.g. studies often combined elements from different theoretical and epistemological traditions). We believe that such an analysis would yield useful insights as it links the methodological issue of sample size to the broader philosophical stance of the research. Despite these limitations, the analysis of the characterisation of sample size and of the threats seen to accrue from insufficient sample size, enriches our understanding of sample size (in)sufficiency argumentation by linking it to other features of the research. As the peer-review process becomes increasingly public, future research could usefully examine how reporting around sample size sufficiency and data adequacy might be influenced by the interactions between authors and reviewers.

The past decade has seen a growing appetite in qualitative research for an evidence-based approach to sample size determination and to evaluations of the sufficiency of sample size. Despite the conceptual and methodological developments in the area, the findings of the present study confirm previous studies in concluding that appraisals of sample size sufficiency are either absent or poorly substantiated. To ensure and maintain high quality research that will encourage greater appreciation of qualitative work in health-related sciences [ 64 ], we argue that qualitative researchers should be more transparent and thorough in their evaluation of sample size as part of their appraisal of data adequacy. We would encourage the practice of appraising sample size sufficiency with close reference to the study at hand and would thus caution against responding to the growing methodological research in this area with a decontextualised application of sample size numerical guidelines, norms and principles. Although researchers might find sample size community norms serve as useful rules of thumb, we recommend methodological knowledge is used to critically consider how saturation and other parameters that affect sample size sufficiency pertain to the specifics of the particular project. Those reviewing papers have a vital role in encouraging transparent study-specific reporting. The review process should support authors to exercise nuanced judgments in decisions about sample size determination in the context of the range of factors that influence sample size sufficiency and the specifics of a particular study. In light of the growing methodological evidence in the area, transparent presentation of such evidence-based judgement is crucial and in time should surely obviate the seemingly routine practice of citing the ‘small’ size of qualitative samples among the study limitations.

A non-parametric test of difference for independent samples was performed since the variable number of interviews violated assumptions of normality according to the standardized scores of skewness and kurtosis (BMJ: z skewness = 3.23, z kurtosis = 1.52; BJHP: z skewness = 4.73, z kurtosis = 4.85; SHI: z skewness = 12.04, z kurtosis = 21.72) and the Shapiro-Wilk test of normality ( p  < .001).

Abbreviations

British Journal of Health Psychology

British Medical Journal

Interpretative Phenomenological Analysis

Sociology of Health & Illness

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Acknowledgments

We would like to thank Dr. Paula Smith and Katharine Lee for their comments on a previous draft of this paper as well as Natalie Ann Mitchell and Meron Teferra for assisting us with data extraction.

This research was initially conceived of and partly conducted with financial support from the Multidisciplinary Assessment of Technology Centre for Healthcare (MATCH) programme (EP/F063822/1 and EP/G012393/1). The research continued and was completed independent of any support. The funding body did not have any role in the study design, the collection, analysis and interpretation of the data, in the writing of the paper, and in the decision to submit the manuscript for publication. The views expressed are those of the authors alone.

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JB and TY conceived the study; KV, JB, and TY designed the study; KV identified the articles and extracted the data; KV and JB assessed eligibility of articles; KV, JB, ST, and TY contributed to the analysis of the data, discussed the findings and early drafts of the paper; KV developed the final manuscript; KV, JB, ST, and TY read and approved the manuscript.

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Additional Files

Additional file 1:.

Editorial positions on qualitative research and sample considerations (where available). (DOCX 12 kb)

Additional File 2:

List of eligible articles included in the review ( N  = 214). (DOCX 38 kb)

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Citations used by articles to support their position on saturation. (DOCX 14 kb)

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Vasileiou, K., Barnett, J., Thorpe, S. et al. Characterising and justifying sample size sufficiency in interview-based studies: systematic analysis of qualitative health research over a 15-year period. BMC Med Res Methodol 18 , 148 (2018). https://doi.org/10.1186/s12874-018-0594-7

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Experiences of teachers who have taught physical education remotely: a qualitative study.

Danielle Causer Brabston , Liberty University Follow

School of Education

Doctor of Philosophy in Education (PhD)

Katelynn Wheeler

Remote education, online physical education, physical education, remote physical education, online learning, physical education teachers

Disciplines

Education | Health and Physical Education

Recommended Citation

Brabston, Danielle Causer, "Experiences of Teachers Who Have Taught Physical Education Remotely: A Qualitative Study" (2024). Doctoral Dissertations and Projects . 5521. https://digitalcommons.liberty.edu/doctoral/5521

The purpose of this qualitative phenomenological study was to understand and describe the essence of the experiences of teachers who have taught physical education remotely. The problem is physical education is a core curriculum subject that is designed for in-person instruction and is not easily adaptable to an online setting. The central research question that this study sought to address was what are the experiences of K-12 physical education teachers who taught P.E. remotely? The theory guiding of this study is Dabrowski’s theory of positive disintegration as it details how people can adapt and adjust in response to stressful situations and adverse events. I chose a phenomenological research method with an exploratory focus. This study was vital to understanding the experiences of teachers who taught physical education in a remote setting. This type of design was most appropriate for this study because understanding the perspectives of the participants was important to be able to identify the unique challenges of the group being studied. The sample size was 10 participants from schools across the United States who have taught physical education remotely for at least one year in a traditional K-12 school. The data collection included answers from the individual interview questions, and information gathered from the focus groups and questionnaires. To analyze the data, I used a form of manual coding. I looked for themes and patterns and significant statements. I then created a list of non-overlapping statements about how the interviewee experienced the phenomenon being studied. This information was used to draft answers to the research questions. The findings indicated that although teaching physical education remotely is challenging, teachers can adapt and find creative ways to address these challenges in order to provide the best possible educational experience for the student, even when teaching physical education remotely.

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Peer-reviewed

Research Article

Barriers to adaptation of environmental sustainability in SMEs: A qualitative study

Roles Conceptualization, Formal analysis, Methodology

Affiliation Faculty of Management Science, Sardar Bahadur Khan Womens’ University, Quetta, Pakistan

Roles Supervision

Affiliation Department of Management Sciences, Balochistan University of Information Technology, Engineering and Management Sciences, Quetta, Pakistan

Roles Funding acquisition, Project administration, Writing – review & editing

Affiliations Graduate Business School, UCSI University, Kuala Lumpur, Malaysia, Management Studies Department, Bahria University Karachi, Karachi, Pakistan

ORCID logo

Roles Writing – original draft, Writing – review & editing

* E-mail: [email protected]

Affiliations Graduate Business School, UCSI University, Kuala Lumpur, Malaysia, Faculty of Management Sciences, Shaheed Zulfikar Ali Bhutto Institute of Science and Technology, Karachi, Pakistan

  • Nazneen Durrani, 
  • Abdul Raziq, 
  • Tarique Mahmood, 
  • Mustafa Rehman Khan

PLOS

  • Published: May 16, 2024
  • https://doi.org/10.1371/journal.pone.0298580
  • Peer Review
  • Reader Comments

Table 1

This study examines the antecedents of environmental sustainability in small and medium enterprises (SMEs) of a developing country and explores the specific internal and external factors for environmental sustainability. The study focused on SMEs in Balochistan, Pakistan, utilizing convenience and purposive sampling techniques to select a sample size of 30 SMEs. In-depth qualitative interviews were conducted using a semi-structured questionnaire. The results of the study revealed that lack of finance and education are major barriers to recognizing and addressing environmental sustainability issues, along with the lack of government support and regulations to ensure compliance with environmental safety laws, hence leading to low concern for sustainability practices among SMEs. Awareness and attitude of SME owners/managers, along with customer demand and government policies, influence the adoption of environmental sustainability practices. Overcoming financial constraints and promoting cooperation among stakeholders are key to fostering sustainable practices in SMEs. This research makes an important contribution to the sustainable management literature by providing new and in-depth insights into the barriers that impede environmental sustainability in SMEs of developing countries.

Citation: Durrani N, Raziq A, Mahmood T, Khan MR (2024) Barriers to adaptation of environmental sustainability in SMEs: A qualitative study. PLoS ONE 19(5): e0298580. https://doi.org/10.1371/journal.pone.0298580

Editor: Agnieszka Konys, West Pomeranian University of Technology, POLAND

Received: July 27, 2023; Accepted: January 28, 2024; Published: May 16, 2024

Copyright: © 2024 Durrani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: The author(s) received no specific funding for this work.

Competing interests: The authors have declared that no competing interests exist.

Introduction

Sustainability is now a critical aspect of development, with growing awareness among people in developing countries [ 1 ]. Climate change and environmental disasters are major threats to the planet and must be addressed through policies that connect the environment, economy, and society for sustainable growth [ 2 ]. To prevent the environment, organizations are striving to adopt sustainable practices and focusing on green practices, processes, and products [ 3 ]. This enables firms to bring positive impacts on organizational performance and the environment. However, ambiguity is still high on how firms can contribute to sustainability, especially in context of small and medium enterprises (SMEs).

SMEs have not received significant attention in the ongoing global discussion about sustainable development [ 4 , 5 ]. It is evident that large organizations impact environment. It is also crucial to acknowledge the pivotal role of SMEs as well. SMEs impact on environment become clearer when we consider their collective impacts. Globally, over 95% of businesses are SMEs [ 6 ]. Although each SME may have little impact, the cumulative effect of SMEs can be substantial due to their large number [ 4 ]. It is often mentioned that SMEs are responsible for major pollution [ 7 ].

Environmental sustainability in SMEs refers to the practice of reducing the environmental impact of business operations while ensuring performance [ 8 ]. This can involve reducing waste, conserving resources, using renewable energy sources, and minimizing carbon emissions [ 8 , 9 ]. However, SMEs face challenges in implementing sustainable practices due to limited resources, lack of access to information, and high initial costs [ 10 ]. This challenge becomes more severe in resource-constrained developing countries.

Researchers have been supporting the adaptation of sustainability practices [ 3 , 11 ]. However, literature has not adequately addressed the sustainability issues faced by SMEs in developing countries as it has with developed ones [ 12 ]. This situation has been widely acknowledged in the literature [ 4 , 5 ]. Wang et al. [ 10 ] shed light on the importance of sustainability initiatives in developing countries and the unique barriers and motivational factors. Similarly, Jabbour et al., [ 4 ] emphasized the significance of sustainability in developing countries and the need to study strategies for achieving sustainable practices. Additionally, Purwandani & Michaud [ 13 ] recognized the necessity to delve into sustainability matters within SMEs as it impacts business performance and presents new market opportunities.

Prior studies showed that organizations should focus on improving economic, environmental, and social sustainability through the triple bottom line approach [ 3 , 14 ]. Albeit, the dynamics of a resource-constrained country are different, thus requiring a different approach to achieve environmental sustainability. Therefore, there is need to explore the barriers and limitations of a developing country before replicating those strategies that work well in developed countries.

In this study we address the gap by exploring the internal and external factors that contribute to achieve the environmental sustainability in SMEs of Pakistan. The present study recognizes the existence of environmental alerts in Pakistan, particularly in Balochistan that comprise great environmental concern and weak governance [ 15 – 17 ]. Hence, this research significantly contributes to the discipline of sustainability. Further, the research framework of this study encompasses environmental orientation, responsible environmental management, and eco-friendly practices, which grounded on strategic competencies such as pollution prevention, product stewardship, and sustainable development of natural resource-based view (NRBV) theory [ 18 , 19 ]. Therefore, this study provides comprehensive understanding of internal and external dimensions of SMEs that need to be nurtured to improve environmental sustainability. While extending the previous research Baah et al. [ 18 ], this research provides new insight for top management, policymakers, governmental and non-governmental organizations (NGOs) for achieving environmental performance in SMEs of developing countries.

Literature review

Factors of environmental sustainability in smes.

Research suggests that customers may prioritize low prices over environmentally friendly practices [ 20 ]. However, some argue that consumers prefer to buy from sustainable companies even if it means paying a slightly higher price [ 21 ]. Though research is not conclusive over consumer buying eco-friendly products from SMEs or big firms, however, it shows consumer preference for sustainable products. Since SMEs are a crucial component of the global economy providing a significant portion of GDP in countries [ 10 ]. Hence, it can be inferred that their collective impact on the environment is also substantial, contributing to 70% of overall pollution [ 7 ]. Environmental sustainability is now a global concern for SMEs and comes under public policy limelight. SMEs may address environmental concerns through waste recycling or pollution prevention [ 22 – 24 ]. Therefore, addressing environmental considerations, it is important to consider both materialistic and non-materialistic approaches, such as production processes or long-term sustainability goals. The business community should also be mindful of resource scarcity and strive for a balance between current utilization and future needs, prioritizing long-term thinking over short-term profits.

SMEs prioritize survival and cost reduction that may not align with environmental sustainability [ 25 ]. The relationship between environmental sustainability and economic outcomes is complex and influenced by multiple factors. However, engaging in environmentally efficient practices can lead to long-term benefits and increased revenue through recycling, reuse and reduce [ 26 ]. Hence, it raised question whether eco-efficiency could increase profits for SMEs [ 27 ]. Researchers suggest that adaptation of sustainable practices and ecological partnerships can lead to financial success for SMEs [ 28 ]. Moreover, Hossain et al. [ 29 ] conducted a systematic literature review of articles published during 2009–2020 and identified 87 drivers of environmental sustainability and categorized them under internal and external dimensions. Researchers suggested that SMEs should focus on internal and external factors for implementation of sustainable practices. Hence, researchers identified internal and external barriers suitable to the context of this study. Table 1 summarizes the barriers and opportunities for SMEs.

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In reality, adopting sustainability requires resources, however, SMEs already facing several challenges [ 30 ]. On the other side, SMEs strive to gain flexibility and adaptability [ 31 ], unfortunately SMEs often lack the resources to implement sustainable practices [ 10 ]. Researchers argue that factors such as time constraints, financial limitations, inadequate training, information access and a lack of environmental management are hindering SMEs in practicing environmental sustainability [ 13 , 32 ]. A limited number of staff and routine work leave no time for learning and implementing sustainability measures [ 32 ]. Hiring professionals to train existing employees can help, however, financial constraints restrict SMEs to invest in knowledge and ability enhancement. Another aspect is employee or manager reluctance towards green innovation due to tight schedule, lack of experience or latest knowledge [ 33 ]. Environmental practices require pro-environmental behavior of employees [ 34 ]. To address this problem, companies should establish a network and enhance their relationship with external partners [ 35 ], such as universities, to provide cost-effective training for their staff. Establishing short-term objectives may facilitate the achievement of long-term goals, allowing SMEs to foster internal sustainability.

The limited financial capital of SMEs creates a significant constraint in SMEs ability to invest in environmental sustainability practices. The impact of these investments on profits remains a lingering question. Despite the potential benefits, SMEs may struggle to sustain the financial burden of implementing environmental sustainability measures [ 36 ]. Consequently, SMEs can apply for grants and loans from government agencies and financial institutions to alleviate financial constraints, which, in return, help them to bring sustainability in process and increase revenue in long term. However, lack of financial support from government and financial institutions and formal lengthy procedures creates hindrances in adopting sustainable practices [ 13 , 37 ]. Despite the awareness and willingness of owners and managers to embrace environmental sustainability, financial constraints prevent them from environmental initiatives or involving third parties [ 38 ].

Moreover, the decision to adopt environmental sustainability practices in SMEs lies with the owners and managers, who act as the decision-makers. Their perception of the benefits associated with pro-environmental behavior is a key factor in determining whether they choose to invest in such practices [ 34 ]. A positive attitude towards environmental sustainability is essential for owners and managers to initiate such practices in their firms [ 38 , 39 ]. Manager’s age determines the adaptation of sustainable practices and concerns for environmental performance [ 40 ]. Education and green entrepreneurial orientation also play a significant role in adopting sustainable practices in SMEs [ 35 ]. SMEs are mostly governed by their owners and family members hence they align their resources with their priority, and survival is the topmost priority. Thus, sustainability may be considered on priority in SMEs when owners, family member or managers have environmental instincts and can foresee that bringing sustainability is new way of survival.

On the other hand, the interests of stakeholders play a significant role in firm’s approach towards environmental sustainability at different levels within the business [ 41 ]. Stakeholders often prioritize financial sustainability over social and environmental sustainability, as long as they receive some sort of return [ 42 ]. Large organizations can establish long-term partnerships with stakeholders and the resources to influence through marketing strategies. Albeit SMEs find it difficult to maintain the relationships in long-term and often have shorter-term relationships with stakeholders, thus making it difficult for SMEs to change their perceptions [ 25 ]. SMEs are supposed to have a responsibility to the community, customers, and employees they serve [ 37 , 38 , 43 ]. Jamali et al. [ 44 ] argue that SMEs operate on a personal level and are closer to their stakeholders due to work-family issues, trust, and employee retention, among other factors. Moreover, when owners see market forces and customers direction towards eco-friendly processes and products, they may shift their focus on sustainability. Researchers claim that owners may not consider sustainability issues until they face a problem and are not motivated to do so as long as they are reaping profits [ 45 ].

Environmental sustainability practices and firm performance

The incorporation of sustainable practices in SMEs is influenced by various factors [ 10 , 13 ]. These factors include the motivation of entrepreneurs to adopt certain practices based on their perception of potential positive financial outcomes or their concerns about the consequences of not embracing eco-friendly approaches [ 46 ]. The actions taken towards sustainability can either positively or negatively impact the financial performance of SMEs. Some researchers suggested that implementing sustainability practices is considered an additional burden by SMEs [ 47 ], while others support that there is positive relationship between firm performance and environmental protection efforts [ 8 , 36 ].

Environmental Management System (EMS) has proven to be highly beneficial for the sustainable development of SMEs. ISO 14001 offers certified guidelines to assist SMEs in reducing their environmental impact and achieving long term sustainability [ 48 ]. By implementing EMS, SMEs can lower energy consumption costs while also creating positive image in the eyes of customers, regulators, and the public. Furthermore, EMS enables SMEs to utilize latest green technology, which not only reduces costs and improves productivity but also minimizes their negative impact on the environment. This innovative approach to resource utilization, cost reduction and environmental preservation ultimately ensures the sustainability of SMEs [ 24 , 49 ]. Additionally, when SMEs collaborate with businesses within their network and receive support from organizations, they become more environmentally innovative and effectively reduce costs [ 22 ]. This ability to leverage network advantages is crucial for SMEs. Subsequently, adoption of environmental practices allows SMEs to position themselves as excellent performers [ 50 ].

Researchers suggested that financial limitations were inversely related to the adoption of practices. However, it also revealed a correlation between access to capital and technological expertise with the implementation of sustainability measures regardless of company size [ 50 ]. Various approaches can be utilized to assess the impact of environmental sustainability practices on firm performance. These include enhancing stability, reducing emissions, improving eco-efficiency systems, conserving materials, energy and implementing ISO 14001 certification [ 9 , 8 , 24 , 48 ]. Performance measures may involve creating environmentally friendly production processes and adopting innovative techniques. By adopting environmental sustainability practices firms can enhance their systems to minimize water usage, air pollution and toxic waste emissions [ 51 ]. Therefore, managers of SMEs who implement sustainability measures often believe in adopting innovative technologies [ 52 ].

The positive impact of effectively implemented EMS, on performance has been evident [ 48 , 53 ]. Therefore, implementation of EMS leads to improved environmental performance, including reductions in water consumption and waste emissions. Previous studies found that the adoption of EMS practices provides benefits to SMEs [ 53 ]. Improvements in environmental performance and cost reduction go hand in hand. Eco-design plays a role in creating products with better recycling potential and improved performance. Furthermore, these eco-friendly designs are not only less harmful but also cost-effective to manufacture, leading to reduced expenses and improved firm performance [ 54 ]. When organizations strive to reduce pollution, it ultimately results in resource utilization and increased productivity. Sustainable practices like recycling and collaborating with suppliers contribute to cost reduction and enhanced efficiency. By utilizing metal scraps, waste materials, and recycled oil within SMEs operations along, with water recycling and purification measures, all contribute to cost reduction while simultaneously boosting profits.

Furthermore, implementing environmental protection initiatives can influence firm image [ 54 ]. Firms’ performance heavily relies on their knowledge-based resources and the ability to effectively utilize these resources to gain advantages [ 52 ]. However, researchers argue that being an eco-friendly organization does not necessarily guarantee strong competitiveness in the market [ 50 ].

Conceptual framework

This study proposes a research model to investigate sustainability in SMEs. Previous studies have examined how internal and external factors affect knowledge and attitudes toward environmentally conscious management practices [ 55 ]. This study included external and internal factors as independent variables, which encompasses suppliers, customers, and laws. These characteristics motivate and challenge management to adopt environmental sustainability initiatives. Stakeholder impact on SMEs is further influenced by environmental awareness and attitudes, which address top management understanding of the cost and benefits of being environmentally sustainable. These variables influence environmental sustainability practices, serving as dependent variable. Hence, external and internal factors influence the organization’s attitude and understanding of environmental sustainability, which defines its policies, strategies, and systems for sustainable development. This process is influenced by owner-manager qualities, time, financial resources, and cost-benefit information about environmental sustainability. Without these criteria, SMEs may struggle to implement environmental sustainability initiatives. The effects of these factors need to be examined in the context of developing countries. Fig 1 depicts the research framework.

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Methodology

The target population for this study was SMEs, defined as firms with fewer than 250 employees [ 56 ], located in Balochistan, Pakistan. The industrial states included in the study were Quetta industrial and trading state, Hub industrial and trading state, Uthal industrial state, and Marble City. Due to the lack of proper records or censuses of SMEs in Balochistan, the researchers used convenience and purposive sampling techniques for data collection [ 57 ].

The data collection method used was a semi-structured interview based on an interviewer-administered questionnaire. This method was chosen because it was believed to provide in-depth understanding of subject matter [ 58 ]. The interview questionnaire was adapted from a similar study by [ 55 ] and revised based on a pilot study and expert opinions to ensure validity and reliability. This research adhered to ethical guidelines, securing respondent consent prior to interviews. Additionally, the authors sought ethical approval from the Institutional Review Board (IRB). However, the IRB returned the application with the recommendation that no ethical review is necessary for this research study. The research process followed in this study is presented in Fig 2 .

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Data collection

Data collection was carried out over a period of five months and involved a combination of convenience and purposive sampling techniques. The study began with a meeting with the head of Small and Medium Enterprises Development Authority (SMEDA) in Balochistan, Pakistan. The starting point for sampling was well-educated SME owners, and initial contact was made through phone calls. Appointments were set after presenting the interviewees with a letter of consent. The data collection process continued for several months in Quetta City, with the majority of manufacturing SMEs located in Hub City. As such, additional time was required for arrangements and contact. The head of the Chamber of Commerce in Hub and the Lasbela Industrial Estate Development Authority (LIEDA) were consulted for support and references to reach SME owners. Due to the conservative and underdeveloped environment in Balochistan and the prevalence of terrorism, the respondents were only met when referred by a reliable reference.

During the interviews, a survey was conducted to determine the respondent’s capability to understand, judge, and answer research questions. The survey questions were designed to obtain responses related to the adoption of sustainable practices in SMEs, and the interviews were conducted in person, demographic information of respondent is shown in Table 2 . The interview method proved beneficial in providing diverse views and answers related to different businesses.

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This study employed non-probability sampling technique; however, efforts were made to ensure that the sample was diverse and representative of the population of SMEs in the region. Moreover, due to the sensitive nature of the topic and the underdeveloped environment in Balochistan, the sample size was limited to 30 SMEs. However, prior studies recommended a sample size of 12–20 for qualitative research [ 59 , 60 ]. Hence, the sample size of this study is deemed acceptable [ 61 ]. Despite these limitations, the present study provides valuable insights into the barriers to sustainable practice adoption in SMEs in Balochistan, Pakistan. Table 3 summarizes the respondent’s answers to interview questions as “yes” or “no” to enable further discussion.

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The collected data from the semi-structured interviews was analyzed using coding techniques and condensed into main themes for further examination [ 62 ], presented in Table 4 . The researcher repeatedly read through the data and utilized word clouds to identify sub-themes, consolidate common themes, and identify main themes, Fig 3 depicts the word clouds. A final review was conducted to identify any important or conflicting information related to the established themes.

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Theme one: Awareness of environmental sustainability

The initial stage of the research process involved an overview of environmental sustainability concerns and an assessment of the level of awareness among owners and senior managers of SMEs. The term sustainability was frequently interchanged with environmental care practices, but the concept of ecopreneurship was relatively unfamiliar to most of the interviewees. However, respondents with higher levels of education generally had a better understanding of environmental protection within their production processes. Meanwhile, those who were less educated did not possess any knowledge in this regard and did not adopt any environmental precautions in their business operations.

When asked about their understanding of the sources and problems of drinking water and electricity in their city, all respondents agreed that these issues were prevalent and that load shedding of electricity had significantly impacted their businesses. Some entrepreneurs were able to survive by relying on alternatives such as solar panels, but others had suffered significant losses. The scarcity of water was another challenge faced by most SMEs, both for drinking and business purposes. Despite the difficulties, most respondents felt that it was not their role as entrepreneurs to preserve water and electricity. Respondents highlighted that the cost of running business was already high, and the additional expense of water testing and purification only added to their burden.

One hotel owner said that “running a hotel is a big responsibility and it increases our cost when we buy water from private vendors , if Quetta did not face the water scarcity problems , then we would also have benefited from it .”

Another owner from a marble factory in Hub City said that “although the water came from Hub Dam and its dependent on the level of rain . Water was there but it was not clean they had to arrange their own purification plants and filters , so that was also an expense . ”

When discussing the firms’ practices in developing products or services with consideration for their environmental impact, it was clear that the environment was not a significant concern for most SMEs. Very few firms had policies in place to minimize negative environmental impact, and these were mostly ISO-certified businesses that dealt with international clients. For the rest of the firms, their focus was on making enough profit to remain competitive in the market rather than considering the environmental impact of their operations.

Manager of steel plant said, “It seems like we should adopt eco-friendly practices not just sake of environment but also for the benefit of our society as well as for profit . ”

While the majority of SME owners tended to recognize the effects of businesses on the environment and the importance of being environmentally conscious, they also expressed their need for government support in this regard. The concept of sustainability was often misunderstood, with many respondents confusing it with environmental issues. However, when the term environmental sustainability was explained to them in detail, they were able to grasp its significance and the importance of considering this issue in their business operations.

Theme two: External factors, environmental awareness, and attitude

The second theme of the study aimed to identify the impact of external factors on environmental sustainability practices. The firms were divided into two categories: those dealing with local customers and those dealing with international customers. Firms dealing with only local customers reported that cost was the primary concern of their customers, while firms dealing with international customers indicated that they were bound to follow certain policies, including environmental policies, to meet international business standards. The companies that were ISO-certified reported that it was mandatory for them to be environmentally sustainable in order to attract international customers.

One respondent said that “its mandatory for them to be environmentally sustainable to capture customers at international level” .

SMEs faced a different set of challenges when dealing with environmentally friendly suppliers and distributors. If the SMEs had multiple choices of suppliers to select from or were bound by their customers to work with environmentally friendly businesses, they opted for environmentally friendly suppliers. On the other hand, SMEs in Balochistan province mainly dealt with local suppliers and distributors who lacked education and awareness about environmental sustainability issues. Most of the marble suppliers in this region belonged to poor communities and were not supported by any government agencies, making them bound to market trends in terms of supply.

The firms that had sufficient knowledge and were aware of the importance of environmental sustainability had adopted methods to be environmentally sustainable, but not to their full potential due to the lack of support from government organizations. They expressed a desire to work towards environmental protection but faced challenges due to the lack of awareness and adoption of environmentally sustainable practices in the supply chain. The focus on cost reduction rather than environmental protection also presented an obstacle. According to the results of the study, the government in Quetta seems to have little to no involvement in promoting environmental sustainability among SMEs. The respondents reported a lack of awareness of any governmental institutions or initiatives aimed at promoting environmentally safe practices.

One respondent said that “now a day’s metropolitan of Balochistan had signed a contract with the Turkish company to manage recycling of waste . ”

According to this new contract, counselors in every area would need to sign a contract and agree to pay a fund in the earliest days to pick up and recycle the waste for few early years, and after some time, when the company gets established, the Turkish company instead of taking money would pay money for managing waste products.

Respondent from oil manufacturing firm said that “LIEDA is playing its role of waste management and EPA (Environmental protection agency) occasionally shows its concern in Hub” .

Theme three: Internal factors, environmental awareness, and attitude

The business performance of various sectors was assessed, and the results were varied. While some businesses, such as restaurants, lubricants, rice dealers, and furniture, were reported to be operating successfully and were financially stable, many others were struggling to survive and expressed concern about their current situation.

A respondent from a tin making firm said that “my business had suffered losses in the past few years but had reached a breakeven point the previous year . However , the business remained at risk as tin was being rapidly replaced by plastic . ”

The manager of a mosaic making firm reported a sluggish financial situation, as the cessation of funding from a donor had resulted in increased expenses while their revenue remained stagnant. The manager attributed this to the low level of awareness and advertising of mosaic products, which primarily cater to high-end society and hotels.

Most of the respondents from the marble factories reported that the industry was facing stiff competition and was plagued by high waste due to a lack of proper machinery. This led to many marble factories closing due to losses, with only a few who had access to modern machinery and cutting-edge technology being able to remain profitable. The remaining businesses were fighting for survival.

SMEs are facing challenges in accessing credit from banks and other financial institutions due to difficult and lengthy bank procedures, high interest rates, and the risk of losing their businesses to repay loans. Some of the SMEs interviewed had positive views about accessing credit, saying that if they were registered and had an NIT number, they would easily get loans. However, even these SMEs were hesitant due to the burdensome procedures involved. A few respondents mentioned that if they had personal contacts with bank officials, they would not face any problems accessing credit. On the other hand, some of the SMEs had negative views and highlighted that they were unable to meet their monetary needs, and they faced difficulties in accessing credit and loans.

Respondents from the marble factory said that “banks nearly took over our business as factory was kept as collateral” .

The CEO of a mosaic making firm said that “SMEs in the mosaic making industry face many difficulties in accessing financial institutions . ”

When asked about the possibility of raising funds for expanding production capacity, the SMEs were divided. Some SMEs in a sound financial position were capable of raising funds from their businesses, family, friends, and relatives, while others were struggling to survive and had no intention of expanding.

The owner of marble company said that “we thought to easily raise funds from the business community and friends , but the current conditions in the Marble City and the downward trend of business made it difficult to attract any further investments” .

On the other hand, a manager from a salt making firm said that “the company had a mission to reinvest , and it could easily raise funds for expansion from equity or risk . ”

Training and development of employees were also a concern for the SMEs. The firms in a sound financial position were willing and able to support their employees, while those struggling to survive were reluctant to do so.

The owner of a rice distribution firm said that “we sent their employees for further education and paid training to keep them competitive and aware of modern business techniques” .

The wheel making and salt refinery firms had training as part of their regular policies, and employees were given training for promotion and continuous learning. However, only a few of the thirty firms interviewed considered their employees valuable assets and invested in their training and development. The availability of financial resources to develop or buy new, environmentally safe production machinery was another concern.

The respondent from a tin plating firm said that “the company wants to take a bank loan for the long-term profitability and better production machinery . ”

The manager of a salt refinery firm said that “expertise in machinery was not available in Pakistan , so we are working on upgrading machinery from foreign sources for better production and environmental safety” .

Some of the oil refining firms made small investments in new equipment for innovation. However, the majority of the marble factories were suffering from a lack of investment in new machinery and did not have government support in this regard. Only a few marble factories that were able to invest in new machinery were earning more profits and were environmentally safe.

One owner from a marble factory said that “we are not interested in investing in new machinery as the business is not future-promising . Although we are in the position to afford it . ”

This is contradictory situation where, at one side, SMEs claim that due to lack of financial resources, they are not able to invest in latest machinery, on the other side, some firms can afford but only invest to see the profit prospect of the business, not the environmental sustainability.

Theme 4: Environmental awareness, attitudes, and environmental sustainability

The culture of an organization is shaped by its employees, with senior managers and owners setting the standards and policies. When asked about their knowledge of environmental sustainability and climate change, the level of education of the respondents was found to be a facilitator or a hindrance. Those with a higher level of education had a better understanding of the topic, while others were less informed. The manager of a mosaic-making firm, who was MPhil scholar, was proud of his company’s adoption of environmentally sustainable practices.

He said that “the company uses leftover marble residuals in the production of mosaic in partnership with an international donor company to turn waste into profit” .

The majority of respondents agreed that being environmentally friendly is good for business. However, a minority who did not agree were conservative in their approach and lacked education and awareness of the benefits of eco-friendly business. The respondent from the mosaic manufacturing SME saw conservation and precautions as long-term investments, while another from a marble factory expressed concern for the environment and the impact it would have on their business if they did not adopt environmentally friendly practices. SMEs that did business internationally, such as marble, mosaic, and salt, stated that being environmentally friendly was part of doing business. These firms reported that international companies refuse to do business with those who do not have an environmental care aspect in their business. The media, including television and the internet, was acknowledged by the respondents for increasing awareness of environmental issues.

Nearly all respondents agreed that religion teaches the importance of ethics and environmental sustainability. For example, one respondent from the marble factory said that their religion emphasizes cleanliness and that being socially and environmentally responsible is part of their belief.

Manager from the oil industry said that “In Islam the first and foremost thing is care of humans and for that ethics bound us to take care of our environment . Religion Islam gives us the teaching that one human should not hurt the other , so if we act upon it then according to this care of others , care of society and care of environment is definitely part of our ethics” .

Most of the firms interviewed saw corporate social responsibility as a tool for creating good will among the public. The respondents from the restaurant industry said that; “According to me the answer is definitely corporate responsibility generates more profits because in our business it all depends on the care of customers , providing them with fresh & healthy food in a healthy & clean environment is the core of our business & that’s possible only if we are careful about the corporate responsibility” .

Established SMEs, such as the tin plating firm, made efforts to fulfill their corporate social responsibilities by planting a water purification plant in a village suffering from polluted water and by running schools. The oil refining firm saw corporate social responsibility as a long-term investment, as it prevents the spread of diseases like hepatitis among their workers and their families. The Marble City respondents expressed their efforts to fulfill their responsibilities but faced hurdles from uneducated workers and non-cooperative labor. Four respondents did not agree that corporate social responsibility and profit margins go together. The manager from the salt industry saw it as a matter of economics rather than social responsibility and stated that their company provides medical facilities and schools for their workers. They believed that thinking about profit and social responsibility at the same time leads to a conflict of interest. All of the participants had a positive opinion, saying that environment is preferable to us, as this is where we live and want it to be secured. They support environmental sustainability being present in all firms, although it may reduce profit.

One respondent said, " As we deal with rice supply , we used to pack our rice in plastic bags but after realizing that this is harmful for the environment we changed to paper bags for packing . Although it increased our cost but for long-term sustainability it seemed more preferable .”

The respondent working at the Parlor had an opinion regarding the presence of environmental sustainability in organizations by saying that “ In our business environmental sustainability does not decrease profit rather , it gives us competitive advantage , when our customers observe us using environmentally friendly products , they come more often and spread good words , resulting in increased customers and more profit .”

One of the business owners stated that business was done for profit, but it was also necessary to care for the environment as it was the home where the business was located. The environment and the earth were the sources of all the resources used in production and it was impossible to move forward without taking care of the environment. Half of the respondents agreed to recycle their production waste when questioned about it, while the other half either had no waste or were unaware of recycling practices. The manager of a tin plating company reported that the water used in their process was recycled and the tin scraps and hardboard leftovers were sold to packing companies for box making. The gems and jewelry company reused their residual materials in fine jewelry and synthetic items. The respondent from a salt company reused salt waste by evaporating water using the sun’s heat. An oil refinery invited experts from Switzerland to help manage their waste and recycling efforts and had reclamation plants to clean dirty oil for reuse. However, the used oil did not receive a proper price. Finally, the respondents who were already working at an international level stated that being environmentally friendly was necessary to do business at an international level. They said that being ISO certified was important to gain international customers as it required firms to operate in an environmentally safe manner. The same was true for restaurant businesses, as they were required to follow policies and criteria to do business at an international level.

Theme five: Environmental practices (policies, strategies, systems)

Most firms interviewed, except for three SMEs, did not have a written policy on environmental sustainability practices. The firms with environmental policies only did so to meet ISO certification requirements. The manager of the wheel manufacturing firm reported having an ISO certification for two years, which includes environmental policy. The oil refinery company also had an environmental policy, which they upgraded periodically.

When asked about resource conservation and waste material reuse, the owners and managers gave varying answers, but the message was consistent that they strive to conserve resources but face opposition from their workers. The manager of the tin plating company said they are trying to replace inefficient heaters with more efficient ones, but their workers are uncooperative. The wheel manufacturing firm has made efforts to conserve water and electricity by switching to energy-saving bulbs. The oil refinery firm efficiently uses the boiler to maximize production. The respondent from Marble City said that despite efforts to conserve electricity and water, uneducated workers often ignore the advice, causing problems for the company. Overall, the respondents agreed that resource conservation leads to cost reduction.

Many SMEs provided general training to their employees on the usage of machinery and chemicals, however, only some of them included environmental perspective in their training. For example, the respondent from the tin plating company stated that their employees were trained to handle chemical waste and use machinery in an environmentally conscious manner, but most of them being uneducated, did not understand the significance. The manager of the oil refinery company mentioned that they did provide training on environmental aspects, as even a small oil leak could cause significant land pollution, which they aim to avoid.

The respondent from the mosaic firm added that their international organization required them to train their employees on various subjects, including the environment. Most of the respondents acknowledged that they tried to guide their employees on environmental protection, but the lack of education was a major hindrance to understanding the concept. However, one of the marble factories, being a big organization, provided step-by-step training to all their employees on various aspects. The owner of the furniture company stated that their employees were trained based on their level of knowledge.

When asked about voluntary environmental programs, the participation of SMEs varied depending on their financial position and level of environmental awareness. For instance, the tin plating company had a water purification plant to conserve water, while the salt-making company focused on providing health care facilities and education rather than environmental programs. The oil refinery company mentioned their hepatitis vaccine campaign as a voluntary program to save the environment from contagious diseases. One of the respondents from Marble City said that his organization was working very efficiently in voluntary environmental programs like tree plantations, etc., but water consumption and costs of purchasing water increased, and he was not able to continue it. The mosaic-making firm stated that their voluntary program involved training females on how to reuse and conserve resources, maximize their income and reduce waste. However, one of the respondents from Marble City mentioned that although their organization was working efficiently on voluntary environmental programs such as tree plantations, the increased water consumption and purchasing costs made it difficult for them to continue these initiatives.

The study aimed to understand the level of awareness among owners and senior managers of SMEs regarding environmental sustainability issues. The results are aligned with strategic abilities of NRBV theory, such as pollution prevention, product stewardship, and sustainable development. NRBV provides support for the theme of this study, which encompasses environmental-orientation, responsible environmental management, and eco-friendly operations.

The qualitative analysis revealed that majority of SMEs owners or managers were not familiar with the term "ecopreneurship." This was primarily due to their low level of education, knowledge, or lack of concern for environmental issues. Researcher argues that environmental practices rely on equal involvement from all employees and lack of knowledge hinders their implementation [ 20 ]. In Balochistan, the shortage of electricity, water, law enforcement and mismanagement are well known [ 16 ]. Every respondent interviewed acknowledged this problem and agreed on the need to conserve these resources. However, the awareness was limited to owners and managers, and they faced difficulties in making their workers understand and address sustainability.

Most SMEs, except for a few that were ISO certified, did not consider environmental impact in their business practices. Firms that obtained ISO certification only did so to expand their international business, as certification was mandatory for international business dealings. These findings are consistent with previous literature suggesting that unawareness and lack of laws are major reasons for environmental harm [ 63 ]. When law enforcement is weak, people tend to harm the environment. However, strict regulations and the fear of punishment may prompt SMEs to make changes that help them understand the costs and benefits of their actions. Hence, external pressure such as regulatory compliance and legal certainty, is a primary motivator for firms to adopt environmental practices [ 18 , 32 ]. Thus, it is important for customers, governments, and supportive organizations to work together to educate and encourage SMEs to adopt environmentally sustainable practices.

Sustainable practices play a critical role for businesses in boosting their market share. Researchers suggested that sustainable practices offer benefits such as enhanced market position, increased customer base, and competitive edge [ 64 ]. In line with previous studies, this study identified that SMEs that are ISO-certified believe they must be environmentally sustainable to capture international customers [ 37 , 38 , 43 , 44 ]. Further, external factors, such as customers, can act as both motivators and obstacles for SMEs in terms of adopting environmentally sustainable practices. However, local customers who are price-sensitive may be hesitant to accept the potential price increases that come with environmentally sustainable practices. Meanwhile, SMEs in Balochistan province face further hurdles as their supply chains come from poor backgrounds, lacking financial resources and government support, forcing them to prioritize their livelihood over environmental sustainability [ 65 ].

The adoption of environmental sustainability practices by SMEs is a subject of debate due to their limited financial capital. It remains unclear whether such investments will result in increased profits or whether SMEs may face financial challenges when engaging in such practices [ 36 ]. On the other hand, applying for grants and loans from government agencies, energy service companies, or non-government organizations can help SMEs overcome financial constraints and pursue environmental sustainability [ 66 ]. However, some studies have suggested that the willingness to adopt environmental sustainability practices has nothing to do with the economics or size of the firm but rather depends on the awareness and attitude of the company [ 67 ]. In the case of the SMEs in Balochistan Province, financial constraints were the main reason for their reluctance to invest in environmentally sustainable practices. While they could have sought financial help from personal sources, the complicated bank process and the prevailing business and security conditions made them hesitant to do so.

The positive mindset and attitude of the owners are crucial in driving environmental sustainability initiatives within the firm [ 38 , 39 ]. SMEs, being owned and operated by their founders, can align their resources with their priorities, including prioritizing long-term sustainability over short-term profits [ 37 ]. If they see benefits in such environmental practices, they may allocate finances towards them, but if they view it as a long-term investment, they may be reluctant to adopt even if they have the means to do so [ 68 ]. The owners and managers may focus on certain sustainability aspects while disregarding others, depending on their mentality [ 69 ]. However, some owners may only consider sustainability issues when they face problems and otherwise prioritize profits over sustainability [ 66 , 67 ].

The limited knowledge of SMEs owners and managers may lead them to believe that pro-environmental measures are costly without considering the long-term benefits, such as the reduction of toxic waste and energy consumption through eco-friendly machinery and practices like using energy-saving light fixtures [ 70 ]. Researchers contended that further incentives are needed to convince SMEs owners to take bolder pro-environmental measures, even if they have already taken initial steps [ 71 ]. Moreover, the study highlights that religion plays a role in shaping attitudes toward environmental sustainability. Nearly all religions teach similar moral values, but the intensity and nature of belief may vary [ 72 ]. Researchers showed a correlation between religion and environmental sustainability [ 73 ], where owners in Balochistan agreed that religion teaches ethical values, but finances, lack of education, and knowledge limit the practical application of these values.

These findings are in collaboration with previous studies that support a positive correlation between environmental awareness and practices among SME owners/managers [ 22 , 52 , 55 ]. This study suggests that SMEs may struggle to implement environmental management practices due to a lack of awareness of their environmental impact. Moreover, environmental awareness is influenced by legislation, leading to formal compliance systems and changes in conservation behavior within SMEs [ 53 ]. The majority of SMEs owners and managers lack the education and research environment to adopt pro-environmental practices, and their attitudes are shaped by media exposure. Some established SMEs practice corporate social responsibility, while others view it as separate from profit-making or as a burden on their income.

Managerial implications

The study provides significant implications for SMEs owners, managers, government, and environmental agencies. First, it is utmost important for both owners and workers to have access to education regarding environmental initiatives and their advantages. Closing the knowledge gap through workshops and training programs is essential, not only for aware SMEs but also to make them stick to eco-friendly protocols. Additionally, government agencies and environmental NGOs should advocate for increased government support and incentives as financial limitations pose a barrier. Second, SMEs should view ISO certification not as a requirement but also as a strategic tool that provides an advantage in accessing international markets. SMEs should engage with customers to raise awareness about the benefits of eco-friendly practices, which can help address customers’ concerns about increased prices. Third, SMEs should position themselves as environmentally friendly organizations that open opportunities for financial support mechanisms such as environmental initiative grants and loans. Fourth, managers should develop CSR strategies that align with SMEs priorities, which create shared value and enhance reputation. Fifth, managers should collaborate with other environmental agencies and establish networks with NGOs and governmental agencies to amplify the impact of sustainability initiatives. Managers should also explore the opportunities for adaptation of climate friendly technologies and processes. Sixth, government agencies should take initiatives to foster a mindset among SMEs owners by emphasizing how sustainability aligns with long term profitability. Finally, government agencies should develop policies to monitor and evaluate environmental initiatives and performance of SMEs, which ensures improvement and adaptation to environmental initiatives. These research implications contribute to long term success and sustainable development of SMEs.

This study examines the impact of internal and external factors on the environmental sustainability of SMEs in Balochistan, Pakistan. The qualitative research method was used to gain a deeper understanding of the motivators and barriers towards environmental sustainability. This study indicated that adoption of environmental sustainability practices by SMEs is influenced by a combination of internal and external factors. Further, awareness and attitude of the company owners and managers play a critical role in implementation of environmentally sustainable practices. Internal factors, such as financial constraints and lack of awareness, were identified as the primary reasons for the limited adoption of environmentally sustainable practices among SMEs in Balochistan province. However, the study also found that applying for grants and loans from government agencies or non-government organizations can help SMEs overcome financial constraints and pursue environmental sustainability. Further, external factors, such as customers and government policies, play a crucial role in promoting environmental sustainability among SMEs. In the similar vein, these internal and external factors significantly influence eco-friendly attitude and awareness of SMEs owners or managers, which leads to overcome barriers such as lack of knowledge, polices, training, and foster positive attitude for adoption of environmental sustainability practices within SMEs.

Supporting information

S1 data set..

https://doi.org/10.1371/journal.pone.0298580.s001

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  1. Big enough? Sampling in qualitative inquiry

    So there was no uniform answer to the question and the ranges varied according to methodology. In fact, Shaw and Holland (2014) claim, sample size will largely depend on the method. (p. 87), "In truth," they write, "many decisions about sample size are made on the basis of resources, purpose of the research" among other factors. (p. 87).

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    Despite varied research topics and approaches to assessing saturation, studies converged on a relatively consistent sample size for saturation for commonly used qualitative research methods. However, these findings apply to certain types of studies (e.g., those with homogenous study populations). Th …

  16. How to Justify Sample Size in Qualitative Research

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  19. Can sample size in qualitative research be determined a priori?

    There has been considerable recent interest in methods of determining sample size for qualitative research a priori, rather than through an adaptive approach such as saturation. Extending previous literature in this area, we identify four distinct approaches to determining sample size in this way: rules of thumb, conceptual models, numerical guidelines derived from empirical studies, and ...

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    The sample size for a study needs to be estimated at the time the study is proposed; too large a sample is unnecessary and unethical, and too small a sample is unscientific and also unethical. The necessary sample size can be calculated, using statistical software, based on certain assumptions. If no assumptions can be made, then an arbitrary ...

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    Problem areas of determining the sample size in qualitative research: a model proposal. Hasan Tutar, Mehmet Şahin, Teymur Sarkhanov. Pages 315-336. Article preview. select article Book review: Qualitative research in education: a review for physics education and other sub-sciences.

  28. Frontiers

    This study used the phenomenological method of qualitative research and semi-structured interviews to understand the psychological experience of IVAP patients with cancer in a top-three hospital in Hunan province, China. This study was approved by the Hunan Normal University Ethics Committee. 2.1 Participants and sample size

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  30. Barriers to adaptation of environmental sustainability in SMEs: A

    Moreover, due to the sensitive nature of the topic and the underdeveloped environment in Balochistan, the sample size was limited to 30 SMEs. However, prior studies recommended a sample size of 12-20 for qualitative research [59, 60]. Hence, the sample size of this study is deemed acceptable . Despite these limitations, the present study ...