RATIONALE

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).

AIMS AND OBJECTIVES

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

METHODS

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

RESULTS

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.

CONCLUSION

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