6.1. Usefulness of quality criteria to evaluate qualitative research

“Whatever the method, it needs to be well-defined, well-argued, and well-executed” (Snijders, 2007)

The increasing demand for qualitative research within health and health services research has emerged alongside an increasing demand for the demonstration of methodological rigor and justification of research findings (Reynolds, 2011) . Not only is qualitative research challenged by the current evidence-based practice (EPB) movement in healthcare, also the emergence of meta-analyses (e.g. meta-synthesis) of qualitative research findings urges for quality criteria. Although in quantitative health sciences research, there exist widely-recognized guidelines, no comparable standardized guidelines exist for qualitative research. This can be explained by a lack of consensus related to how to best evaluate “rigor” in qualitative research ^{(Nelson, 2008)}. Every qualitative paradigm has its own implications regarding the definition of good quality research. First, we  introduce the reader briefly in the debate about quality criteria, second, we present the framework of Walsh and Downe (Walsh, 2006) as the most complete and comprehensible list of quality criteria to appraise qualitative research studies, and the framework of Côté and Turgeon as a shorter and practical alternative. For other checklists we refer to Appendix 1.

Among qualitative researchers there is a debate going on between those demanding for explicit criteria, for example in order to serve systematic reviewing and evidence-based practice, and those who argue that such criteria are neither necessary nor desirable^{(Hammersley, 2007)}. The quest for quality criteria assumes that qualitative research is a unified field, but this image does not fit reality. In fact, apart from a variety of other positions (e.g. symbolic interactionism, hermeneutics, phenomenology, ethnography) three main paradigms can be discerned in relation to this discussion:

• The interpretativistparadigm assumes that social realities are multiple, fluid and constructed. This framework values research that illuminates subjective meanings and multiple ways of seeing a phenomenon. These researchers question the need for and the utility of quality criteria for qualitative research or apply specific criteria for qualitative research, such as clear delineation of the research process, evidence of immersion and self-reflection, demonstration of the researcher’s way of knowing (e.g. tacit knowledge)^{(Cohen, 2008)}.
• The positivist approach stands at the other end of the continuum and assumes that there is a single objective reality that is knowable. Positivists apply traditional quantitative criteria, such as validity and reliability to qualitative work.
• The realist perspective is positioned in between. It maintains a belief in an objective reality, but knowledge of reality is always imperfect^{(Cohen, 2008)}. Realists use techniques such as triangulation, member validation of findings, peer review of findings, deviant or negative case analysis and multiple coders of data, to promote to verify findings. The realist perspective adopts a philosophy of science that is in line with positivism, but at the same time embracing the complexity of social life and recognizing the importance of social meanings. “By maintaining a belief in an objective reality and positing truth as an ideal qualitative researchers should strive for, realists have succeeded at positioning the qualitative research enterprise as one that can produce research which is valid, reliable, and generalizable, and therefore, of value and import equal to quantitative biomedical research” ^{(Cohen, 2008,}p. 336).

The position one takes in the debate about quality criteria is heavily influenced by the paradigm one feels most attracted to, or identifies with.