Data, epistemic values, and multiple methods in case study research

Case Study research is characterized by the employment of multiple data gathering methods. In this paper, I examine the concurrent use of participant observation and qualitative interviews. The question I examine is: what is the rationale behind their combination in case study research? In the literature on case study research, the two most common reasons for using multiple methods appeal to comprehensiveness and convergent confirmation respectively. I argue that there is a third significant, yet overlooked, way to motivate the joint use of participant observation and qualitative interviews: the methods may generate complementary evidence and this puts the researcher in a better position to confirm that her data manifest central epistemic values and so are suitable as a basis for providing an adequate answer to her research question. I refer to this as the rationale of "blended epistemic value validation".