Study design in qualitative research--2: Sampling and data collection strategies.

In two prior papers in our series on qualitative research [Frankel & Devers (2000a, 2000b) Qualitative research: a consumer's guide, Education for Health, 13, 113-123; Frankel & Devers (2000) Study design in qualitative research-1: developing research questions and assessing research needs, Education for Health, 13, 251-261], we examine two critical issues in qualitative research design: sampling, including identifying and negotiating access to research sites and subjects, and data collection and management. We describe these two key steps in the qualitative research design process, discuss challenges that often emerge when pursuing these steps, and provide guidelines for addressing them. Qualitative research most often uses "purposive," rather than random, sampling strategies. A good understanding of these sampling strategies and why they are used is central to designing a credible qualitative study. In addition, given the real-world context in which most qualitative research is carried out, identifying and negotiating access to research sites and subjects are critical parts of the process. We also provide suggestions for developing and maintaining productive and mutually satisfying research relationships with sites and subjects. Finally, data collection and management are often neglected subjects in qualitative research. We offer practical advice on how to collect and manage qualitative data, including factors to consider when deciding how structured the data collection process should be, the pros and cons of audio- and/or videotaping compared with note-taking, and tips for writing up field notes and document management. A forthcoming, final paper in the series will focus on qualitative data analysis and the publication of qualitative research results.