Assessing rigor in qualitative research.

Two recent research columns have addressed reliability and validity in quantitative studies. Quantitative research designs involve the measurement of human characteristics, usually with the assignment of numerical values to each, and the mathematical analysis and summary of findings. Multiple characteristics of large numbers of research participants are summarized as numerical “averages” or trend indicators, which can be analyzed in relation to one another. This has been regarded as the scientific approach to the description of reality. Qualitative research methods, in contrast, are intended to describe the human experience as it is lived, generally through the careful collection and analysis of narrative, subjective qualitative materials. With grounding in the social sciences and philosophy, investigators who use naturalistic approaches probe deeply into the complexity of human beings. It is assumed that people shape and create their own experiences and that truth is perspectival, that is, reflective of one’s own historical and sociocultural context. There are many truths, and each person’s truth has inherent value for those who seek to understand human experiences. The fullest possible truth requires the examination of a phenomenon from varying points of view. For example, the history of the Civil War will be different from the perspective of northerners versus southerners; from the perspective of the descendents of slaves versus the descendents of plantation owners; from the perspective of men versus women. Yet all perspectives will contribute to the “truth” of that history. It is often the case that qualitative studies that describe a lived human experience precede quantitative studies involving large numbers of participants, in which the way characteristics are interrelated is evaluated. Qualitative studies tend to be conducted in natural settings, that is, “in the field.” The investigator is the research instrument. That is, the investigator records all data, including transcripts, observations, and subsequent personal reflections, and categorizes and then interprets them. Because the pool of participants in qualitative studies tends to be smaller, and recruited by convenience or purposively rather than randomly, the potential for the investigator’s personal values and attitudes to influence the report of findings is great. In fact, this has been amajor source of criticism of qualitative research designs (Polit&Hungler, 1999).Quantitativemethods are based on the premise that clear protocols lead to the collection of objective data, which will then be subjected to analysis by a value-free computer. In contrast, qualitativemethods are based on the premise that the investigator will identify relevant personal history, values, and attitudes that may bear on the situation, acknowledge them, and then bracket them, or set them aside, in determining how the data can best be clustered and summarized. The investigator’s own contribution to the dialogue that constitutes the data set is understood to be highly relevant. Note that we could consider this to be a more honest approach, because scientists, who are after all human beings operating within a cultural context, cannot ever attain true objectivity. The framing of any research question reflects the investigator’s assumptions, values, and attitudes. Still, maintaining rigor in a qualitative study is of paramount concern to investigators.When planning or evaluating a qualitative study, it is appropriate to evaluate the rigor or “trustworthiness” (Streubert & Carpenter, 1999) using various criteria. Credibility or dependibility has to dowith the “truth” of the findings. One factor that contributes to credibility is the length Research Column