Setting events are typically seen as antecedent contextual variables that influence behaviour. They are thought to act independently of Skinner's three-term contingency, which consists of a discriminative stimulus, response, and reinforcing consequence. There has been increasing interest in setting events in education from both a theoretical and applied perspective. This paper examines a range of conceptualisations of setting events and appraises the extent to which they can be viewed as a discrete class of phenomena. Variation in the terminology used to describe setting events and lack of clarity in consideration of explanatory mechanisms tends to hinder analysis. Nevertheless, a number of plausible explanations exist to account for setting events associated with both conditioned and unconditioned reinforcers. While the conceptual underpinnings of setting events remain unclear in part, they do serve the function of drawing our attention to a wide range of antecedent variables that may influence behaviour. Resolution of issues related to consistency of terminology and clarification of our conceptual understanding of setting events may provide further guidance in their practical application to behaviour. (Contains 1 figure.)