The realist approach to evaluation research: an introduction

Background: The realist approach is a form of theory-driven evaluation developed to strengthen the explanatory power of evaluation studies and contribute to evidence-based policy and practice. It is a generic approach that can be applied to many fields of research, including health and social care. Content: This article introduces the reader to the realist approach and outlines its application in empirical evaluation studies and literature syntheses. It describes how the realist researcher evaluates complex social interventions not by asking whether a particular programme or intervention ‘works’, but, recognising that all interventions only ever work for certain people in certain circumstances, by asking instead ‘what works for whom in what circumstances’? Realist researchers then try to articulate the theories (termed ‘mechanisms’) that underpin the programme and explore how contexts influence the mechanisms to produce different programme outcomes. Conclusions: Realist evaluation and realist synthesis are an advanced approach to evaluation research, but they offer an innovative and insightful means by which to further our understanding of complex social interventions.