Redefining Representativeness of a Sample in Causal Terms

Despite its crucial role, sample representativeness remains a controversial topic in the methodology of medical science. There is an ongoing debate not only about how best to define and ensure the representativeness of a sample (e.g., Rudolph et al. 2023; Porta 2016), but also about whether representativeness is worth pursuing at all (e.g., Rothman et al. 2013).

Our aim is to construct a formalised, precise, and practical conceptualisation of sample representativeness.

We employ the established framework of causal Bayesian networks to develop such a conceptualisation.

We propose a precise formal definition of sample representativeness that translates into clear and actionable methodological guidance. Additionally, we provide examples and a checklist to illustrate the application of the proposed conceptualisation.

We believe that the presented definition will facilitate further discussion of the issue of representativeness and prove useful to scientists in practice.