Qualitative Research Part II: Participants, Analysis, and Quality Assurance.

T his is the second of a two-part series on qualitative research. Part 1 in the December 2011 issue of Journal of Graduate Medical Education provided an introduction to the topic and compared characteristics of quantitative and qualitative research, identified common data collection approaches, and briefly described data analysis and quality assessment techniques. Part II describes in more detail specific techniques and methods used to select participants, analyze data, and ensure research quality and rigor. If you are relatively new to qualitative research, some references you may find especially helpful are provided below. The two texts by Creswell 2008 and 2009 are clear and practical. In 2008, the British Medical Journal offered a series of short essays on qualitative research; the references provided are easily read and digested. For those wishing to pursue qualitative research in more detail, a suggestion is to start with the appropriate chapters in Creswell 2008, and then move to the other texts suggested. To summarize the previous editorial, while quantitative research focuses predominantly on the impact of an intervention and generally answers questions like ‘‘did it work?’’ and ‘‘what was the outcome?’’, qualitative research focuses on understanding the intervention or phenomenon and exploring questions like ‘‘why was this effective or not?’’ and ‘‘how is this helpful for learning?’’ The intent of qualitative research is to contribute to understanding. Hence, the research procedures for selecting participants, analyzing data, and ensuring research rigor differ from those for quantitative research. The following sections address these approaches. T A B L E 1 provides a comparative summary of methodological approaches for quantitative and qualitative research. Data collection methods most commonly used in qualitative research are individual or group interviews (including focus groups), observation, and document review. They can be used alone or in combination. While the following sections are written in the context of using interviews or focus groups to collect data, the principles described for sample selection, data analysis, and quality assurance are applicable across qualitative approaches. Selecting Participants