The following module discusses reliability and validity in qualitative research, with an emphasis on establishing credibility and transferability.
- Define and reliability and validity in qualitative research
- Discuss the importance of establishing validity
- List strategies used by researchers to improve reliability and validity
Qualitative research is based on subjective, interpretive, and contextual data, making the findings are more likely to be scrutinized and questioned. Therefore, it is critical that researchers take steps to ensure the reliability and validity of their research findings. The findings must be believable, consistent, applicable, and credible if they are to be useful to readers and other researchers.
Reliability refers to consistency with which the research will produce the same results if repeated. Validity refers to accuracy or correctness of the findings. The following video provides an excellent introductory overview to reliability and validity, including an explanation of terms and specific examples.
Qualitative research has become increasingly popular in the past two decades. Therefore, much time has been spent reviewing ways to judge the reliability and validity of qualitative research findings. To withstand the scrutiny, researchers should spend time giving serious consideration to the following four aspects:
- Credibility - Often called internal validity, refers to the believability and trustworthiness of the findings. This depends more on the richness of the data gathered than on the quantity of data. The participants of the study are the only ones that decide if the results reflect the phenomena being studied and therefore, it is important that participants feel the findings are credible and accurate. Triangulation is a commonly used method for verifying accuracy that involves cross-checking information from multiple perspectives. The link in Resources Links on the left describes different types of triangulation methods.
- Transferability - Often called external validity, refers to the degree that the findings of the research can be transferred to other contexts by the readers. This means that the results are generalizable and can be applied to other similar settings, populations, situations and so forth. Researchers should thoroughly describe the context of the research to assist the reader in being able to generalize the findings and apply them appropriately.
- Dependability - Otherwise known as reliability, refers to the consistency with which the results could be repeated and result in similar findings. The dependability of the findings also lends legitimacy to the research method. Because the nature of qualitative research often results in an ever-changing research setting and changing contexts, it is important that researcher document all aspects of any changes or unexpected occurrences to further explain the findings. This is also important for other researchers who may want to replicate the study.
- Confirmability - A measure of the objectivity used in evaluating the results, describes how well the research findings are supported by the actual data collected when examined by other researchers. Researchers bring their own unique perspectives to the research process and data interpretation can be somewhat subjective in qualitative research. If findings are corroborated or confirmed by others who examine the data, then no inappropriate biases impacted the data analysis.
Altheide, D. L., & Johnson, J. M. (1994). Criteria for assessing interpretive validity in qualitative research.
Kvale, S. E. (1989). Issues of validity in qualitative research. Studentlitteratur.
Miller, M. L. (1986). Reliability and validity in qualitative research. Sage.
Onwuegbuzie, A. J., & Leech, N. L. (2007). Validity and qualitative research: An oxymoron?. Quality & Quantity, 41(2), 233-249.
Smith, J. A. (Ed.). (2007). Qualitative psychology: A practical guide to research methods. Sage.
Whittemore, R., Chase, S. K., & Mandle, C. L. (2001). Validity in qualitative research. Qualitative health research, 11(4), 522-537.