What’s in a mechanism? Development of a key concept in realist evaluation

Using a social science illustration, we argue that disaggregating the concept of mechanism into its constituent parts helps to understand the difference between the resources offered by the intervention and the ways in which this changes the reasoning of participants. This in turn helps to distinguish between a context and mechanism. The notion of mechanisms 'firing' in social science research is explored, with discussions surrounding how this may stifle researchers' realist thinking. We underline the importance of conceptualising mechanisms as operating on a continuum, rather than as an 'on/off' switch. The discussions in this article will hopefully progress and operationalise realist methods. This development is likely to occur due to the infancy of the methodology and its recent increased profile and use in social science research. The arguments we present have been tested and are explained throughout the article using a social science illustration, evidencing their usability and value.