MIXED METHODS AND CROSS-CUTTING APPROACHES
21 Realist Evaluation
Sarah Louart, Habibata Baldé, Émilie Robert, and Valéry Ridde
Abstract
Realist evaluation is based on a conception of public policies as interventions that produce their outcomes through mechanisms that are only triggered in specific contexts. The analysis of these links between contexts, mechanisms and outcomes is therefore at the heart of this approach. This approach can be based on a variety of methods, but will in all cases use qualitative methods to investigate the mechanisms involved. Belonging to the family of theory-based evaluations, realist evaluation aspires to produce middle range theories that will facilitate the transfer of the knowledge produced on the intervention under study to other contexts or other interventions of the same type.
Keywords: Qualitative methods, theory-based evaluation, context-mechanism-outcome (CMO) configurations, middle range theory, critical realism
I. What does this approach consist of?
Critical realism, a school of thought led in particular by Roy Bhaskar (1975), paved the way for the development of the realist approach to evaluation. In his book A Realist Theory of Science, he asks: what must the world be like for science to be possible? The idea is to question the nature of reality, since this will then determine how it can be explored and understood. Bhaskar argues that there are structures, powers, mechanisms (e.g. gravity) that exist and can produce effects, even if we do not know them. A leaf can fall from the tree and reach the ground under the effect of gravity, even if we have not observed it. The aim is then to try to produce knowledge about the mechanisms, powers, structures that exist and the ways in which they act, including the conditions that favour their triggering and the effects they can produce. These theories are therefore ‘statements about the way things act in the world’ (Bhaskar 1975). The aim of researchers is then to produce theories that will try to elucidate the existence of mechanisms and the way they operate. However, these theories will always be perfectible and evolving, as reality and knowledge evolve. For ‘realist’ researchers, there is a reality, but there are no general truths that are valid at all times and in all places.
The realist approach to policy evaluation is based on these principles (Pawson and Tilley 1997; Westhorp et al. 2011; Westhorp 2014; Robert and Ridde 2020). It was introduced by Pawson and Tilley (1997). The presupposition is that policies have real effects, but do not cause them directly. They may or may not trigger mechanisms, which in turn produce outcomes. Mechanisms refer to the ways people react to the resources, sanctions or opportunities (depending on the type of intervention) made available to them within the policy framework (Lacouture et al. 2015). People are therefore the drivers of change; it is their reactions that will produce outcomes, whether positive, negative, expected