The terms metacognition, self-regulation, and self-regulated learning appear frequently in the educational literature and are sometimes used interchangeably. In order to explore the theoretical and empirical boundaries between these three constructs and the perceptions or misperceptions that their broad and often unqualified application may engender, an analysis of their use within contemporary research was undertaken. A PsychInfo database search was conducted and 255 studies were identified for a comprehensive data table. Analysis of these data revealed trends that suggest nesting of the constructs in definition and keyword explication. However, important differences emerged in the measures of these three constructs and in environmental factors such as prompting. Implications for future research are discussed.