These findings suggest that under some study conditions, rich qualitative findings can be discovered with relatively small sample sizes. Further determining the parameters under which this applies would be helpful to researchers and research participants alike. Most efforts thus far have been done with studies relying on individual interviews, and many are within the medical field. In addition, examinations of minimal required sample sizes that examine available interviews once, in the order they were collected, raise concerns about possible temporal bias. We sought to examine the minimum sample sizes needed to adequately include the themes and codes in areas of inquiry within the field of social work. Considering three distinct qualitative research studies inclusive of both individual interviewing and focus group data collection approaches, we addressed four research questions: (1) What minimum sample size is needed to adequately identify codes (smaller units of meaning) within the data? (2) What minimum sample size is needed to ensure that all larger themes are partially represented by at least one of the codes that comprise that theme? (3) What minimum sample size is needed to fully realize the complete dimensionality of all themes by including all assigned codes? (4) Are minimum sample sizes needed consistent across different substantive areas of exploration and different modes of data collection, specifically individual interviews and focus groups? To address temporal bias, we addressed these questions by examining multiple random draws of various sample sizes within each included qualitative study.
Social Work Research
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Young, Diane S. and Casey, Erin A., "An Examination of the Sufficiency of Small Qualitative Samples" (2018). Social Work & Criminal Justice Publications. 500.