Can sample size in qualitative research be determined a priori?
By J. Sim, B. Saunders, J. Waterfield, Tom Kingstone. 2018
626 citations recorded by the source corpus.
ABSTRACT There has been considerable recent interest in methods of determining sample size for qualitative research a priori, rather than through an adaptive approach such as saturation. Extending previous literature in this area, we identify four distinct approaches to determining sample size in this way: rules of thumb, conceptual models, numerical guidelines derived from empirical studies, and statistical formulae. Through critical discussion of these approaches, we argue that each embodies one or more questionable philosophical or methodological assumptions, namely: a naïve realist ontology; a focus on themes as enumerable ‘instances’, rather than in more conceptual terms; an incompatibility with an inductive approach to analysis; inappropriate statistical assumptions in the use of formulae; and an unwarranted assumption of generality across qualitative methods. We conclude that, whilst meeting certain practical demands, determining qualitative sample size a priori is an inherently problematic approach, especially in more interpretive models of qualitative research.
Subfields: Education, Social Psychology, Sociology and Political Science
View Paper: https://www.semanticscholar.org/paper/e99358125c2d41f7a46ceef868c11dbb8bb1ab86
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Citations in the corpus
- Saturation controversy in qualitative research: Complexities and underlying assumptions. A literature review (2020, methodology): “Reiterating meaning saturation Sim et al. (2018) propose that it is essential to consider not only how many times the theme emerges but its analytic conceptualisation, thus move from descriptive meaning of the theme to its interpretive cogency.”
- ‘Define, Explain, Justify, Apply’ (DEJA): An analytic tool for guiding qualitative research sample size (2021, background): “…an iterative, context-dependent decision made during the analytical process as the researcher begins to develop an increasingly comprehensive picture of the developed themes, the relationship between these themes, and where the conceptual boundaries of these themes lie’ (Sim et al., 2018a, p. 630).”
- Describing Populations and Samples in Doctoral Student Research (2021, background): “…presented to provide some numerical guidance to novice researchers of the sample sizes one may expect when conducting research using qualitative designs and is based primarily upon a conceptual models approach (Sim et al., 2018) to satisfy the need to achieve data saturation (Fusch & Ness, 2015).”
- DETERMINING THE SAMPLE SIZE IN QUALITATIVE RESEARCH (2020, methodology): “Most funding bodies impose upon the researchers to estimate and provide the number of units included in a sample (Guest et al., 2006; Baker și Edwards, 2012; Sim et al., 2018; Kindsiko & Poltimäe, 2019).”