Are validity and reliability "relevant" in qualitative evaluation research?

Interest in and use of qualitative methodological strategies in evaluating research have increased considerably in the last few years. Many of the recent evaluation frameworks or models are entirely or partly oriented toward use of qualitative methods. A number of methodological issues and concerns have been raised, including the appropriateness of validity and reliability estimation for the measurement strategies employed in qualitative evaluations becoming more common in health and other fields. In this article, the views of prominent qualitative methodologists on this topic are briefly summarized; a case is made for the relevance of validity and reliability estimation; definitions of validity and reliability for qualitative measurement are presented; and appropriate estimation techniques are suggested. It is hoped that discussions such as this will promote increased attention to validity and reliability concerns in qualitative evaluations and thus help improve the quality of those evaluations.