Quality of qualitative research

Quality in qualitative research speaks to the soundness of the entire research endeavour, to the rigorous application of design, theory, methods, analysis, writing, and dissemination (Flick, 2007a). Questions of quality have also been raised in qualitative health research because the positivist notions of quality – validity, reliability, replicability – do not apply. The debates about how to judge quality in qualitative research are ongoing, and qualitative scholars have argued that the criteria used in the (post-)positivist paradigm are incommensurate with the expectations and criteria used for research conducted under interpretive and critical social paradigms (Eakin & Mykhalovskiy, 2003 ). Theoretical congruence is a key criterion to assess the quality of a study (Taylor & Francis, 2013). This means that theoretical assumptions of the particular paradigm should logically link with methodology and methods, and the research questions must be consistent with the central concepts of the chosen theory and must be appropriate for the chosen methodology.

A well-established approach has been proposed by Guba (1981) who coined the concept of “trustworthiness” to judge quality in qualitative research. This umbrella concept includes five criteria – credibility, plausibility, transferability, dependability, and confirmability – that can be met through transparent methodological practices such as researcher reflexivity, audit trails, triangulation^[1], constant comparison, purposeful/theoretical sampling, thick descriptions of phenomena under study, and addressing atypical or negative cases. Depending on the paradigm in which the researcher is working and the methodology that is guiding the study, some criteria will be more appropriate than others. For instance, theoretical sampling is typically used in grounded theory methodology, which allows researchers to discuss “theoretical saturation” as a criterion for establishing the quality of their research. “Saturation” cannot simply be claimed without justifications that are appropriate for the methodological approach taken.

Triangulation is another criterion that is not always applicable, as when a study utilizes a single method for data generation. Researchers in the interpretive paradigm argue against its use because of its positivist undertone. Triangulation in (post-)positivist research is about using multiple sources of information to confirm, for example, what participants say, to find out ‘the truth’. In the interpretive paradigm, the aim is not to verify if what participants say is repeated in interviews and focus groups, but rather to achieve depth and breadth to the phenomenon being studied (Eakin & Mykhalovskiy, 2003 ). Tracy (2010) critiques existing parallel forms of criteria such as triangulation and saturation that play to a dominant and positivist understanding of the scientific method, because they equate quality with ideas about validity based on neutrality, or objectivity and reliability. Others before her have suggested these criteria are problematic because they “ask Catholic questions of Methodist audiences” (Lincoln, Lynham & Guba, 2011: p. 118) . In other words, the quality of qualitative research must be judged according to the tenets of the approach taken (which further suggests that an intra-paradigmatic critique is more powerful and fairer). This approach highlights the importance for qualitative researchers to learn about the theoretical foundations of qualitative inquiry and to carefully consider their design features and rigour strategies.