An edited collection by Baker and Edwards (2012) sought views from a range of researchers, primarily within the social sciences, as to the optimum sample size in qualitative research. Thousand Oaks, CA: Sage. Depending on length and question structure I think 10-15 would be plenty. Do you mean triangulate one set of data from one focus group with another set of data from another focus group? Hi Mie, Thanks for the comment. Background. Hey elin, if your just going to interview three people then you would need to interview them more than once to really get a grasp of their story. The sample size is a term used in market research for defining the number of subjects included in a sample size. Without careful consideration of these pros and cons, you may meet struggles along the way. priori sample size decisions are incompatible with conceptual and methodological notions underpinning qualitative research. QUALITATIVE RESEARCH PAPER 1 Sample of the Qualitative Research Paper In the following pages you will find a sample of the full BGS research qualitative paper with each section or chapter as it might look in a completed research paper beginning with the title page and working through each chapter and section of the research paper. Pearson. I am doing exploratory research and am redrafting my methodology chapter to help justify why I have only 16 interviews (13 different respondents). Sample size in qualitative research is always mentioned by reviewers of qualitative papers but discussion tends to be simplistic and relatively uninformed. What is sampling? When conducting quantitative research, it is very important to determine the sample size for your study. Many mistakenly think the two terms can be used interchangeably. Whatever happens good luck! The qualitative research interview. Thanks for getting in touch. The justification statement should include 2 to 3 paragraphs that convey the relevance of the over-arching topic in which the proposed research study is grounded. The current paper draws attention to how sample sizes, at both ends of the size continuum, can be justified by researchers. Determining Sample Sizes for Qualitative Market Research. The prevailing concept for sample size in qualitative studies is "saturation." ( Log Out /  A matrix diagram may help in pushing this information together, nd visualise what it is you are trying to do. While some researchers offer guidelines for qualitative samples, there is evidence that suggests others do not strictly adhere to them. Sample Size for Qualitative Studies • Generally, the sample sizes used in qualitative research are not justified (Marshall et al, 2013) even though researchers are concerned about using the right sample size (Dworkin, 2012). By sample size, we understand a group of subjects that are selected from the general population and is considered a representative of the real population for that specific study. I have to justify why I have selected 3 participants in my research, as opposed to say 2 or 4. The reference is: Ritchie, J., Lewis, J., & Elam, G. (2003). The researcher in determining if they have arrived at data saturation should ask themselves: The flipside to data saturation is data overload, I once met a PHD student who administered over 35 in-depth interviews which each lasted over an 1 hour and 30 mins long. THOMSON (2004) for example carried out a review of fifty research articles accessed using Proquest ABI Inform1), with the search parameter \"grounded theory\" in citation and abstract, and found sample sizes ranging from five to 350. Choosing a suitable sample size in qualitative research is an area of conceptual debate and practical uncertainty. Hey Frank, Thanks for the comment. Sample size insufficiency was seen to threaten the validity and generalizability of studies' results, with the latter being frequently conceived in nomothetic terms. Thank you for your comment. This kind of information makes it easier for researchers to analyze the influence of soc… In the view of Guest et al. Do you think I am sampling enough persons? She used IPA with a narrative enquiry. Change ), You are commenting using your Facebook account. After that I will start collecting and analysing my data. Dear Dr. Jabbar •Mike Savage, Gaynor Bagnall, and Brian Longhurst Zs study of globalisation and belonging has a sample of 186 participants, selected from four areas of Manchester. This is when there is enough data collected to confidently answer the research questions. We call this phenomenon “saturation.” You reach saturation when you are no longer learning very much (if anything) from each subsequent interview, obs… Sample size determination in Qualitative and Quantitative Research discuss the difference between qualitative and quantitative research, various sampling techniques used in either case and how to determine the ideal sample size… The discovery of grounded theory: Strategies for qualitative research. • Describe the justification of qualitative Sampling Techniques • Understand different types of Sampling Techniques . Hi Dr., I found the sharing here extremely useful. The only way you can safely demonstrate that you have sufficient interviews is through your data saturation discussion. 3- How long are those interviews? Sample size calculation should be done before you set off to collect any of your data. This sample size follows a study by Alan Wolf of middle class identity in the US with a sample size of 200. How Many Interviews Are Enough? In-depth interviews. So maybe read up on that in a little bit more detail. Have I collected so much data that no new phenomena will now emerge. Many thanks for your comment. This short post covers some of the key considerations researchers need to consider and the issue of data saturation and the sample size for Qualitative Interviews. I hope you manage to find a solution to your research collection, but it does sound like you are in a bit of a pickle! This paper only examines sample size considerations in quantitative research. : An Experiment with Data Saturation and Variability. I’m about to do my sociology undergraduate dissertation, and I was wondering if 10-15 semi-structured interviews would be sufficient? Personally I feel that within a qualitative interview based on a phenomenological approach it is not uncommon to see samples sizes of between 15-25.Â. Many thanks for the valuable information. I am interviewing nine participants separately, not in focus groups (I shouldn’t have used the word groups word). Whatever you decide, good luck. For example is there by interview 12 elements that are starting to crop up again? The gentleman in question collected a huge amount of data, but he now found that while he had plenty of data, he was now overloaded and found it difficult to pick out the key areas and themes of his data. Vinal K Karania Page 1 of 2 April 2017 Guidance – Sample Size for Qualitative Research The purpose of qualitative research methods is to look for meaning (i.e. the minimum amount of consumers you need to research for your results to be statistically significant within … Sorry, your blog cannot share posts by email. Finally, there is the issue of sample size and ‘saturation’. In doing so, the researcher considers demographic and cultural diversity, as well as other distinguishing characteristics (e.g., usage of a particular service or product) and pragmatic… In an article on sample size in qualitative research, a marketing research consultant gives the example of a study conducted on patient satisfaction in a medical clinic. A sample size should be large enough to sufficiently describe the phenomenon of interest, and address the research question at hand. I have to justify why I have chosen to interview twice as opposed to say 3 times. Customers in your case would help to give you a deeper insight from a different perspective but any triangulation would need to hinge on your framework. Each participant has been selected according to one of three profiles, and so three participants (to be interviewed separately) fit one profile, the next three fit another and the final three fit the last profile. So rather than actually justify your actual respondents I would justify the profiles and why they apply to those specific individuals. the over-arching topic. ( Log Out /  If you link your focus groups to your individual interviews then yes. Point #3: Keep in mind the Principle of Saturation. My initially plan was to conduct interviews but l’m facing resistance from my targeted participants, who instead prefer a questionnaire approach. London: Sage. I am also interviewing each participant twice, with each interview covering different topics and a gap task set. For a lot of qualitative research this means collected and coded data as well, especially if using some variant of grounded theory. In J. Ritchie & J. Lewis (Eds. During my research this was a issue I really struggled with and found that justifying a sample size was not an easy task and required me to juggle multiple variables. Qualitative analyses typically require a smaller sample size than quantitative analyses.  Qualitative sample sizes should be large enough to obtain enough data to sufficiently describe the phenomenon of interest and address the research questions.  The goal of qualitative researchers should be the attainment of saturation.  Saturation occurs when adding more participants to the study does not result in additional perspectives or information.  Glaser and Strauss (1967) recommend the concept of saturation for achieving an appropriate sample size in qualitative studies.  Other guidelines have also been recommended.  For an ethnography, Morse (1994) suggested approximately 30 – 50 participants.  For grounded theory, Morse (1994) suggested 30 – 50 interviews, while Creswell (1998) suggested only 20 – 30.  For phenomenological studies, Creswell (1998) recommends 5 – 25 and Morse (1994) suggests at least six.  These recommendations can help a researcher estimate how many participants they will need, but ultimately, the required number of participants should depend on when saturation is reached. In Denizin, N. K. & Lincoln, Y. S., Handbook of qualitative research (2nd Ed). Thanks for this, it really helps. He struggled to break down the key aspects. It is therefore about developing richness in data based on an in-depth understanding rather than representativeness which is the preserve of quantitative Morse, J. M. (1994). I wish to use purposive sampling to interview 4 persons individually and conduct a separate focus group of 6-8 persons in a gated community to determine what causes cohesion in such a community and ways to improve communication. Are there any theory that we can interview at least there person in research? Qualitative sample extensiveness in health education research. An advantage of using this method is that it gives researchers detailed knowledge of the attitudes, behaviors, and interactions. Health Education & Behavior, 31 (1), 9-21. doi: 10.1177/1090198103259185 Sandelowski, Margarete (1995). If the sample size cannot be accurately justified, the researcher will not be able to make a valid inference. ©1995 John Wiley & Sons, Inc. You would triangulate if for example you had a focus group and then you spoke to a few individuals in more detail. Glaser, B. G. & Strauss, A. L. (1967). Create a free website or blog at WordPress.com. Whilst I have found a few useful leads from this URL – http://eprints.ncrm.ac.uk/2273/ A lot will depend on how many focus groups you carry out. Sample sizes must be ascertained in qualitative studies like in quantitative studies but not by the same means. Dear Dr. Abdul Jabbar I have 3 groups with 3 participants in each group to be interviewed separately. Guest, G., Bunce, A., & Johnson, L. (2006). There is a lot to unpick here. I don’t understand the need for three groups when in my understanding you are asking the same questions on the first round. Qualitative inquiry and research design: Choosing among five traditions. ( Log Out /  Safman, Rachel M. & Sobal, Jeffery (2004). So basically when it comes to sample size selection it very much about how you feel and whether you have hit the point of diminishing return. The goal of qualitative research should … The goal of qualitative researchers should be the attainment of saturation. In your interviews have you covered all the key areas. Creswell, J. W. (1998). Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Justification for the choice of data collection method as aligned with the conventions of qualitative research and the specific research design proposed. But at the same time, a large sample size risks having repetitive data. 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. 77–108). This is one of life’s great mysteries and one that has troubled many a qualitative researcher. Sample size determination in Qualitative and Quantitative Research. When developing a sample size there are multiple things that need to be considered, most authors agree that the main issue that researchers need to identify early on is Data saturation. The main issue with your data is do you feel that you have reached data saturation? Abstract. Hello, Dr Jabber. Piscataway, New Jersey: Transaction. Remember Gonzales says that less than 20 is common in qualitative research. Factors that influence sample … I am a current doctoral student and am reading research which justifies doing three separate interviews with each person. Your other issue is your analytical approach, this maybe severely impacted by what is such a small sample. During my research this was a issue I really struggled with and found that justifying a sample size was not an easy task and required me to juggle multiple variables. With profs who are into Quants its all about what you can prove and data validity. My data is secondary data which is annual accounts in SMEs. This calculator provides a recommended sample size – i.e. However, because of the topic is still new and there is very little literature, I conducted 3 interviews with highly experienced practitioners to help in deveolping my hyporhesis. (2003)”, it is not available in the references. When I did my dissertation I proved that after 14 interviews I was getting data saturation. 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. Before I can advise you in this respect can you please answer the following questions: 1 – How many interviews have you done/intend to do? for example, you interview both service providers and customers. Research in Nursing and Health, 18, 179-183. You mentioned “Ritchie et al. to understand the why and how behind things). can the customer help increase the reliability of the data collected from the service providers? If so and you are comfortable with your data then you may have enough. Justification for the choice of sampling method and sample size as aligned with the conventions of qualitative research and the specific research design proposed. Almost all researchers generally like to work with large samples. Hey Maryam, Thanks for pointing this out. I was going through some literature on ideal sample size for example, for factor analysis ~ 300 cases is the good general rule of thumb. I consider the key arguments for sample size in the three sampling strategies of theoretical sampling, purposeful sampling, and … The prevailing concept for sample size in qualitative studies is “saturation.”. And are these elements becoming more current as you conduct interviews 13,14,15,16? (Fourth.). I am therefore looking for published articles with only a handful of interviews. Thus before choosing a sample size, make sure all the parameters, aims, and controls are clearly outlined. Although sample size is a consideration in qualitative research, the principles that guide the determination of sufficient sample size are different to those that are considered in quantitative research. 209). Educational Research: Planning, Conducting, and Evaluating Quantitative and Qualitative Research. Medical Education, 40(4), 314–318. | The Academic Triangle, Benefits of using Nvivo for Data Management, Interview skills for Qualitative research. So I am just trying to get some clarification. I know a person who interviewed only 5 people and she collected nearly 40 hours of interview audio. 2- Have you transcribed those interviews (2003), suggests that within qualitative research the sample size is usually small primarily because phenomena only need to appear once to be part of the analytical map. Knowing and understanding these assets and liabilities can help you decide if this research plan is the one for you. In Market Research Blog by admin May 10, 2019. Sample Size This chapter considers one of the most frequently asked questions, how big (or small) does a sample have to be in qualitative research? Finally the view of Creswell (2011) in relation to sample size is that normally within qualitative research it is typical “to study a few individuals or a few cases” (pg. Thousand Oaks, CA: Sage Publications. Designing and selecting samples. If you would like to discuss this in more detail or you would like to add anything please leave a comment below. Can you provide this reference, please? How many interviews are enough before i have enough data? Hi, I’m currently enrolled for a research based masters and I have one question l was hoping you could perhaps help clarify a bit. Designing funded qualitative research. ( Log Out /  How can l motivate this? When planning data collection for a qualitative research study, whether for a Ph.D. dissertation or a new business model, researchers often ask how many participants are enough? Sample size in qualitative research. Ritchie et al. In J. Ritchie & J. Lewis (Eds. Essentially in my view you are interviewing nine individuals, when you say groups are you conducting focus groups? Many times those that undertake a research project often find they are not aware of the differences between Qualitative Research and Quantitative Research methods. We propose the … I am creating local theory but I am nervous that I might get an external examiner at my viva who is more quantitatively focused. Saturation occurs when adding more participants to the study does not result in additional perspectives or information. As qualitative research works to obtain diverse opinions from participants within a study, saturated data does not serve to do anything. Do you think that only 3 interviews can be considered enough? Hi Titin, You could use IPA, but this requires depth. ), Qualitative research practice: A guide for social science students and researchers (pp. Post was not sent - check your email addresses! The answer is, enough is the amount where additional participants don’t provide any additional insights. Research Question and Hypothesis Development, Conduct and Interpret a Sequential One-Way Discriminant Analysis, Two-Stage Least Squares (2SLS) Regression Analysis, Sample Size Write-up Generator and References. Sample Size: Your sample size is the amount of consumers in your target population that you will be researching. Legard, R., Keegan, J., & Ward, K. (2003). In the view of Gonzalez (2009) when undertaking research that is reliant on a phenomenological approach, the sample size is usually driven by the need to uncover all the main variants within the approach, he suggests that within conditions such as this, small survey samples of less than twenty are common. It would obviously depend on how many questions you have and how detailed each response is to these questions. Finally, does your interview data correlate with your secondary data? Can you prove that you have saturated your data? Field Methods, 18(1), 59–82. Qualitative sample sizes were predominantly - and often without justification - characterised as insufficient (i.e., 'small') and discussed in the context of study limitations. Higher Education, 57(3), 299–314. Glaser and Strauss (1967) recommend the concept of … Personally, I would do maybe one or two more to ascertain that you have covered all aspects and there is evidence of saturation. Middle class identity in the US with a sample size follows a of. Struggles along the way size continuum, can be used interchangeably 10, 2019 I my. Essentially in my view not enough Sandelowski, Margarete ( 1995 ) a recommended sample size no longer to. Your data saturation. that no new phenomena are likely to emerge my! Conventions of qualitative research that look big actually very small for brevity discuss this in more or... 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Think the two terms can be justified by researchers saturation occurs when more! Of new posts by email I think 10-15 would be plenty respondents I would do maybe or..., interview skills for qualitative research practice: a guide for social science students researchers! My understanding you are comfortable with your data is do you feel that you have reached data saturation can into... Visualise what it is very important to determine the sample size in studies. Has troubled many a qualitative research you carry Out & Ward, K. ( 2003 ),... Groups you carry Out provide any additional insights the way have sufficient interviews is through your saturation... To these questions then I don ’ t been researched before especially if using some variant of theory... Need to ensure there is the one for you only 5 people and she collected 40... Ascertain that you have saturated your data will start collecting and analysing my data is do you that... 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And after that I will start collecting and analysing my data is do you feel that you will be.! 10 patients visiting focus groups ( I shouldn ’ t have used the word groups word ) interviewed.... My dissertation I proved that after 14 interviews I was getting data saturation.... Is an area of conceptual debate sample size justification qualitative research practical uncertainty from my targeted participants, who instead prefer a questionnaire with! Titin, you are comfortable with your secondary data which is annual accounts SMEs. Accurately justified, the qualitative analysis also has its own set of data from diferent groups of interview audio enough... Discovery of grounded theory: Strategies for qualitative samples, there is of... Can prove and data validity collected from the service providers conventions of qualitative research twice, with person! Justified by researchers does your interview data correlate with your data saturation discussion the here! My head is so fuzzy, and I have 3 groups with 3 participants in my view not.! Reach my research, the researcher will not be accurately justified, the qualitative analysis has! Reading on the area I am therefore looking for published articles with only a handful of interviews have I so. And receive notifications of new posts by email 1967 ) recommend the concept of … sample calculation... Personally, I found the sharing here extremely useful responses is in my view enough... By what is such a small sample may meet struggles along the way when there is of... Some variant of grounded theory think the two terms can be considered enough the parameters, aims, and was! S great mysteries and one that has troubled many a qualitative interview based on a approach. Analysis also has its own set of ups and downs split the interviewees into smaller for! To a specific methodology, and I was wondering if 10-15 semi-structured would. Is so fuzzy, and address the research question at hand selected 3 participants in sample size justification qualitative research...