Toward an understanding of students' allocation of study time: why do they decide to mass or space their practice?

Two recent studies have led to discrepant findings regarding students' decisions to mass or space practice of to-be-learned items: Son (2004) reported that participants chose to mass practice of difficult items more than that of easy items, whereas Benjamin and Bird (2006) reported the opposite. To resolve this apparent discrepancy, we had participants study items during an initial trial and then decide whether the next study trial would be massed or spaced. Across three experiments, we systematically varied factors that differed across these studies. In general, the participants more often chose to space than to mass practice, but they did favor massed practice when items were very difficult to learn. Moreover, although previous hypotheses implicated metamemory causes for these effects, the present results indicate that nonmetamemory causes are also responsible, such as using spaced practice as a default and deciding to mass practice for items that had not been fully perceived during an initial study trial.