Research Article
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Determining Sample Size in Qualitative Research: Data Saturation

Year 2023, Volume: 7 Issue: 2, 138 - 152, 25.12.2023
https://doi.org/10.38122/ased.1030365

Abstract

In qualitative research (in-depth and focus group interviews), the fact that the researcher begins to hear the same comments over and over means that data saturation has been reached. It is used as a criterion for stopping data collection and / or analysis in qualitative research. Interviews should be continued by researchers until they fully understand the perspectives of the participants. There are different studies on how many participants or how many focus groups are saturated. This study aimed to evaluate the qualitative examination of the concept of saturation used in determining the sample size in research and postgraduate studies at the PhD level health workers about the thesis in Turkey. The "National Thesis Center" database was used to determine the studies to be included in the study. Some limitations were taken into account in the determination of the studies, and 45 doctoral dissertations made in the field of health, in which in-depth and focus group interview techniques were used, constituted the scope of the study. Document analysis technique was used in the examination of these studies. It was observed that saturation approach was used in 51.1% of these studies. It has been determined that only the 17.8% of the researches are explained in detail in the saturation approach. Similarly, it was found that in-depth interviews (84.4%) were used more than focus group interviews (15.6%), and saturation was achieved more rapidly in in-depth interviews. In addition, studies using focus group interviews showed that four or five focus groups were formed and the number of people in the groups varied between five and ten. Our findings and researches show that saturation point is widely used in qualitative research. The main issue discussed here is not whether the saturation point should be used in researches or not, but it should be used correctly

References

  • Ando, H., Cousins, R., & Young, C. (2014). Achieving saturation in thematic analysis: Development and refinement of a codebook. Comprehensive Psychology, 3, 1-5. doi:10.2466/03.CP.3.4
  • Bernard, R. & Bernard, H. (2013). Social Research Methods: Qualitative and Quantitative Approaches. London: SAGE.
  • Bertaux, D. (1981). From the life-history approach to the transformation of sociological practice. Biography and society: The life history approach in the social sciences. California: SAGE Publications.
  • Boddy, C.R. (2016). Sample size for qualitative research. Qual Market Res Int J., 19(4), 426-432. doi:10.1108/QMR-06-2016-0053
  • Carlsen, B. & Glenton, C. (2011). What about N? A methodological study of sample-size reporting in focus group studies. BMC Med. Res. Methodol., 11(26), 1-10. doi:10.1186/1471-2288-11-26
  • Charmaz, K. (2006). Constructing Grounded Theory: A Practical Guide Through Qualitative Analysis. London: SAGE.
  • Christie, C.A. & Fleischer, D.N. (2010). Insight into evaluation practice: A content analysis of designs and methods used in evaluation studies published in North American evaluation-focused journals. Am J Eval., 31(3), 326-346. doi:10.1177/1098214010369170
  • Corbin, J.M. & Strauss, A.L. (1990). Grounded theory research: Procedures, canons, and evaluative criteria. Qual. Sociol., 13(1), 3–21. doi:10.1007/BF00988593
  • Creswell, J.W. (2016). Nitel Araştırma Yöntemleri: Beş Yaklaşıma Göre Nitel Araştırma Ve Araştırma Deseni. Ankara: Siyasal Kitabevi.
  • Dey, I. (1999). Grounding Grounded Theory. San Francisco, CA: Academic Press.
  • Dworkin, S.L. (2012). Sample size policy for qualitative studies using in-depth interviews. Arch Sex Behav., 41, 1319–1320. doi:10.1007/s10508-012-0016-6
  • Flick, U. (2009). The Sage Qualitative Research Kit: Collection. London: SAGE Publications Limited.
  • Fossey, E., Harvey, C., McDermott, F., & Davidson, L. (2002). Understanding and evaluating qualitative research. Australian & New Zealand Journal of Psychiatry, 36(6), 717-732. doi:10.1046/j.1440-1614.2002.01100.x
  • Francis, J.J., Johnston, M., Robertson, C., Glidewell, L., Entwistle, V., Eccles, M.P. & Grimshaw, J.M. (2010). What is an adequate sample size? Operationalising data saturation for theory-based interview studies. Psychol. Health., 25(10), 1229-1245. doi:10.1080/08870440903194015
  • Fusch, P. & Ness, L. (2015). Are we there yet? Data saturation in qualitative research. Qual. Rep., 20(9), 1408-1416.
  • Glaser, B.G. & Strauss, A.L. (2017). Discovery of Grounded Theory: Strategies for Qualitative Research. New York: Routledge.
  • Grady, M.P. (1998). Qualitative and action research: A practitioner handbook. Phi Delta Kappa International. Arch Sex Behav., 41, 1319–1320.
  • Green, J. & Thorogood, N. (2018). Qualitative Methods for Health Research. London: SAGE.
  • Guest, G., Bunce, A. & Johnson, L. (2006). How many interviews are enough? An experiment with data saturation and variability. Field Method., 18(1), 59-82. doi:10.1177/1525822X05279903
  • Kitto, S. C., Chesters, J., & Grbich, C. (2008). Quality in qualitative research. Medical Journal of Australia, 188(4), 243-246.
  • Kitzinger, J. (1995). Qualitative research: introducing focus groups. BMJ., 311, 299-302. doi:10.1136/bmj.311.7000.299
  • Langford, B.E, Gerald, S. & Izzo, G. (2002). Nominal grouping sessions vs. focus groups. Qual Market Res Int J., 5, 58–70. doi:10.1108/13522750210414517
  • Low, J. (2019). A pragmatic definition of the concept of theoretical saturation. Soci Focus., 52(2), 131-139. doi:10.1080/00380237.2018.1544514
  • Marshall, B., Cardon, P., Poddar, A. & Fontenot, R. (2013). Does sample size matter in qualitative research?: A review of qualitative interviews in IS research. J Comput Inform Syst., 54(1), 11-22. doi:10.1080/08874417.2013.11645667
  • Mason, M. (2010). Sample size and saturation in PhD studies using qualitative interviews. Forum Qual Soc Res. 11(3), 1-19. doi:10.17169/fqs-11.3.1428
  • Mays, N., & Pope, C. (2000). Assessing quality in qualitative research. BMJ, 320(7226), 50-52. doi:10.1136/bmj.320.7226.50
  • Morse, J. M. (2015). Data were saturated... Qualitative Health Research, 25(5), 587-588. doi:10.1177/1049732315576699
  • Morse, J.M. (1995). The significance of saturation. Qual Health Res., 5, 147–149. doi:10.1177/104973239500500201
  • Morse, J.M. (2000). Determining sample size. Qual. Health Res., 10(1), 3-5. doi:10.1177/104973200129118183
  • Namey, E., Guest, G., McKenna, K., & Chen, M. (2016). Evaluating bang for the buck: a cost-effectiveness comparison between individual interviews and focus groups based on thematic saturation levels. Am J Eval., 37(3), 425-440. doi:10.1177/1098214016630406
  • Nelson, J. (2017). Using conceptual depth criteria: addressing the challenge of reaching saturation in qualitative research. Qual. Res., 17(5), 554-570. doi:10.1177/1468794116679873
  • Onwuegbuzie, A. J., & Leech, N. L. (2007). Sampling designs in qualitative research: Making the sampling process more public. Qualitative Report, 12(2), 238-254.
  • Patton, M. Q. (2005). Qualitative research. Encyclopedia of Statistics in Behavioral Science, 3(1), 1633–1636. doi:10.1002/0470013192.bsa514
  • Reilly, M. & Parker, N. (2013). Unsatisfactory Saturation’: a critical exploration of the notion of saturated sample sizes in qualitative research. Qual Res., 13(2), 190-197. doi:10.1177/1468794112446106
  • Ritchie, J., Lewis, J., Nicholls, C.M. & Ormston, R. (2013). Qualitative Research Practice: A Guide for Social Science Students and Researchers. London: SAGE.
  • Saunders, B., Sim, J., Kingstone, T., Baker, S., Waterfield, J. & Bartlam, B. (2018). Saturation in qualitative research: exploring its conceptualization and operationalization. Qual Quan., 52(4), 1893-1907. doi:10.1007/s11135-017-0574-8
  • Toloie-Eshlaghy, A., Chitsaz, S., Karimian, L., & Charkhchi, R. (2011). A classification of qualitative research methods. Research Journal of International Studies, 20(20), 106-123.
  • Wray, N., Markovic, M. & Manderson, L. (2007). Discourses of normality and difference: Responses to diagnosis and treatment of gynaecological cancer of Australian women. Soc. Sci. Med., 64(11), 2260-2271. doi:10.1016/j.socscimed.2007.02.034

Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu

Year 2023, Volume: 7 Issue: 2, 138 - 152, 25.12.2023
https://doi.org/10.38122/ased.1030365

Abstract

Nitel araştırmalarda (derinlemesine ve odak grup görüşmelerinde), araştırmacının aynı yorumları tekrar tekrar duymaya başlaması, veri doygunluğuna ulaşıldığı anlamına gelmektedir. Doygunluk yaklaşımı, nitel araştırmada veri toplama ve / veya analizinin durdurulması için bir kriter olarak kullanılmaktadır. Bu yaklaşımda, katılımcıların bakış açıları tam anlaşılana kadar görüşmeler araştırmacılar tarafından devam ettirilmektedir. Diğer yandan, kaç katılımcı ya da kaç odak grupta doygunluk sağlandığına dair farklı araştırmalar bulunmaktadır. Bu çalışmada, nitel araştırmalardaki örneklem büyüklüğünün belirlenmesinde kullanılan doygunluk kavramının incelenmesi ve Türkiye’de sağlık çalışanları ile ilgili doktora düzeyinde yapılan lisansüstü tezlerin değerlendirilmesi hedeflenmiştir. Çalışmaya dahil edilecek araştırmaların belirlenmesinde "Ulusal Tez Merkezi" veri tabanı kullanılmıştır. Araştırmaların belirlenmesinde bazı kısıtlılıklar dikkate alınmış, derinlemesine ve odak grup görüşme tekniklerinin kullanıldığı sağlık alanında yapılmış 45 doktora tezi çalışmanın kapsamını oluşturmuştur. Bu araştırmaların incelenmesinde doküman incelemesi tekniği kullanılmıştır. Araştırmaların %51,1’inde doygunluk yaklaşımının kullanıldığı gözlemlenmiştir. Araştırmaların sadece %17,8’inde referans gösterilerek doygunluk yaklaşımının detaylı bir şekilde açıklandığı belirlenmiştir. Aynı şekilde, derinlemesine görüşmelerin (%84,4) odak grup görüşmelerine (%15,6) göre daha fazla kullanıldığı ve derinlemesine görüşmelerde daha hızlı bir şekilde doygunluğa ulaşıldığı tespit edilmiştir. Ayrıca, odak grup görüşmelerinin kullanıldığı araştırmalarda dört ya da beş odak grup oluşturulduğu ve gruplardaki kişi sayısının da beş ile on arasında değiştiği görülmüştür. Elde ettiğimiz bulgular ve yapılan araştırmalar, doygunluk noktasının nitel araştırmalarda yaygın olarak kullanıldığını göstermektedir. Buradaki tartışılan temel husus, doygunluk noktasının araştırmalarda kullanılıp kullanılmaması değil, doğru ve şeffaf bir şekilde kullanılması gerektiği üzerine olmuştur.

References

  • Ando, H., Cousins, R., & Young, C. (2014). Achieving saturation in thematic analysis: Development and refinement of a codebook. Comprehensive Psychology, 3, 1-5. doi:10.2466/03.CP.3.4
  • Bernard, R. & Bernard, H. (2013). Social Research Methods: Qualitative and Quantitative Approaches. London: SAGE.
  • Bertaux, D. (1981). From the life-history approach to the transformation of sociological practice. Biography and society: The life history approach in the social sciences. California: SAGE Publications.
  • Boddy, C.R. (2016). Sample size for qualitative research. Qual Market Res Int J., 19(4), 426-432. doi:10.1108/QMR-06-2016-0053
  • Carlsen, B. & Glenton, C. (2011). What about N? A methodological study of sample-size reporting in focus group studies. BMC Med. Res. Methodol., 11(26), 1-10. doi:10.1186/1471-2288-11-26
  • Charmaz, K. (2006). Constructing Grounded Theory: A Practical Guide Through Qualitative Analysis. London: SAGE.
  • Christie, C.A. & Fleischer, D.N. (2010). Insight into evaluation practice: A content analysis of designs and methods used in evaluation studies published in North American evaluation-focused journals. Am J Eval., 31(3), 326-346. doi:10.1177/1098214010369170
  • Corbin, J.M. & Strauss, A.L. (1990). Grounded theory research: Procedures, canons, and evaluative criteria. Qual. Sociol., 13(1), 3–21. doi:10.1007/BF00988593
  • Creswell, J.W. (2016). Nitel Araştırma Yöntemleri: Beş Yaklaşıma Göre Nitel Araştırma Ve Araştırma Deseni. Ankara: Siyasal Kitabevi.
  • Dey, I. (1999). Grounding Grounded Theory. San Francisco, CA: Academic Press.
  • Dworkin, S.L. (2012). Sample size policy for qualitative studies using in-depth interviews. Arch Sex Behav., 41, 1319–1320. doi:10.1007/s10508-012-0016-6
  • Flick, U. (2009). The Sage Qualitative Research Kit: Collection. London: SAGE Publications Limited.
  • Fossey, E., Harvey, C., McDermott, F., & Davidson, L. (2002). Understanding and evaluating qualitative research. Australian & New Zealand Journal of Psychiatry, 36(6), 717-732. doi:10.1046/j.1440-1614.2002.01100.x
  • Francis, J.J., Johnston, M., Robertson, C., Glidewell, L., Entwistle, V., Eccles, M.P. & Grimshaw, J.M. (2010). What is an adequate sample size? Operationalising data saturation for theory-based interview studies. Psychol. Health., 25(10), 1229-1245. doi:10.1080/08870440903194015
  • Fusch, P. & Ness, L. (2015). Are we there yet? Data saturation in qualitative research. Qual. Rep., 20(9), 1408-1416.
  • Glaser, B.G. & Strauss, A.L. (2017). Discovery of Grounded Theory: Strategies for Qualitative Research. New York: Routledge.
  • Grady, M.P. (1998). Qualitative and action research: A practitioner handbook. Phi Delta Kappa International. Arch Sex Behav., 41, 1319–1320.
  • Green, J. & Thorogood, N. (2018). Qualitative Methods for Health Research. London: SAGE.
  • Guest, G., Bunce, A. & Johnson, L. (2006). How many interviews are enough? An experiment with data saturation and variability. Field Method., 18(1), 59-82. doi:10.1177/1525822X05279903
  • Kitto, S. C., Chesters, J., & Grbich, C. (2008). Quality in qualitative research. Medical Journal of Australia, 188(4), 243-246.
  • Kitzinger, J. (1995). Qualitative research: introducing focus groups. BMJ., 311, 299-302. doi:10.1136/bmj.311.7000.299
  • Langford, B.E, Gerald, S. & Izzo, G. (2002). Nominal grouping sessions vs. focus groups. Qual Market Res Int J., 5, 58–70. doi:10.1108/13522750210414517
  • Low, J. (2019). A pragmatic definition of the concept of theoretical saturation. Soci Focus., 52(2), 131-139. doi:10.1080/00380237.2018.1544514
  • Marshall, B., Cardon, P., Poddar, A. & Fontenot, R. (2013). Does sample size matter in qualitative research?: A review of qualitative interviews in IS research. J Comput Inform Syst., 54(1), 11-22. doi:10.1080/08874417.2013.11645667
  • Mason, M. (2010). Sample size and saturation in PhD studies using qualitative interviews. Forum Qual Soc Res. 11(3), 1-19. doi:10.17169/fqs-11.3.1428
  • Mays, N., & Pope, C. (2000). Assessing quality in qualitative research. BMJ, 320(7226), 50-52. doi:10.1136/bmj.320.7226.50
  • Morse, J. M. (2015). Data were saturated... Qualitative Health Research, 25(5), 587-588. doi:10.1177/1049732315576699
  • Morse, J.M. (1995). The significance of saturation. Qual Health Res., 5, 147–149. doi:10.1177/104973239500500201
  • Morse, J.M. (2000). Determining sample size. Qual. Health Res., 10(1), 3-5. doi:10.1177/104973200129118183
  • Namey, E., Guest, G., McKenna, K., & Chen, M. (2016). Evaluating bang for the buck: a cost-effectiveness comparison between individual interviews and focus groups based on thematic saturation levels. Am J Eval., 37(3), 425-440. doi:10.1177/1098214016630406
  • Nelson, J. (2017). Using conceptual depth criteria: addressing the challenge of reaching saturation in qualitative research. Qual. Res., 17(5), 554-570. doi:10.1177/1468794116679873
  • Onwuegbuzie, A. J., & Leech, N. L. (2007). Sampling designs in qualitative research: Making the sampling process more public. Qualitative Report, 12(2), 238-254.
  • Patton, M. Q. (2005). Qualitative research. Encyclopedia of Statistics in Behavioral Science, 3(1), 1633–1636. doi:10.1002/0470013192.bsa514
  • Reilly, M. & Parker, N. (2013). Unsatisfactory Saturation’: a critical exploration of the notion of saturated sample sizes in qualitative research. Qual Res., 13(2), 190-197. doi:10.1177/1468794112446106
  • Ritchie, J., Lewis, J., Nicholls, C.M. & Ormston, R. (2013). Qualitative Research Practice: A Guide for Social Science Students and Researchers. London: SAGE.
  • Saunders, B., Sim, J., Kingstone, T., Baker, S., Waterfield, J. & Bartlam, B. (2018). Saturation in qualitative research: exploring its conceptualization and operationalization. Qual Quan., 52(4), 1893-1907. doi:10.1007/s11135-017-0574-8
  • Toloie-Eshlaghy, A., Chitsaz, S., Karimian, L., & Charkhchi, R. (2011). A classification of qualitative research methods. Research Journal of International Studies, 20(20), 106-123.
  • Wray, N., Markovic, M. & Manderson, L. (2007). Discourses of normality and difference: Responses to diagnosis and treatment of gynaecological cancer of Australian women. Soc. Sci. Med., 64(11), 2260-2271. doi:10.1016/j.socscimed.2007.02.034

Details

Primary Language Turkish
Subjects Social and Humanities Education (Excluding Economics, Business and Management)
Journal Section Research Article
Authors

Fedayi YAĞAR 0000-0002-3436-6583

Publication Date December 25, 2023
Acceptance Date November 28, 2023
Published in Issue Year 2023Volume: 7 Issue: 2

Cite

APA YAĞAR, F. (2023). Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu. Aksaray Üniversitesi Sosyal Bilimler Enstitüsü Dergisi, 7(2), 138-152. https://doi.org/10.38122/ased.1030365
AMA YAĞAR F. Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu. ASED. December 2023;7(2):138-152. doi:10.38122/ased.1030365
Chicago YAĞAR, Fedayi. “Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu”. Aksaray Üniversitesi Sosyal Bilimler Enstitüsü Dergisi 7, no. 2 (December 2023): 138-52. https://doi.org/10.38122/ased.1030365.
EndNote YAĞAR F (December 1, 2023) Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu. Aksaray Üniversitesi Sosyal Bilimler Enstitüsü Dergisi 7 2 138–152.
IEEE F. YAĞAR, “Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu”, ASED, vol. 7, no. 2, pp. 138–152, 2023, doi: 10.38122/ased.1030365.
ISNAD YAĞAR, Fedayi. “Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu”. Aksaray Üniversitesi Sosyal Bilimler Enstitüsü Dergisi 7/2 (December 2023), 138-152. https://doi.org/10.38122/ased.1030365.
JAMA YAĞAR F. Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu. ASED. 2023;7:138–152.
MLA YAĞAR, Fedayi. “Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu”. Aksaray Üniversitesi Sosyal Bilimler Enstitüsü Dergisi, vol. 7, no. 2, 2023, pp. 138-52, doi:10.38122/ased.1030365.
Vancouver YAĞAR F. Nitel Araştırmalarda Örneklem Büyüklüğünün Belirlenmesi: Veri Doygunluğu. ASED. 2023;7(2):138-52.