Speeding lectures to make time for retrieval practice: Can we improve the efficiency of interpolated testing?

Abstract

Testing is increasingly recognized as an important tool in learning. One form of testing often used in lectures, particularly recorded lectures, is interpolated testing wherein tests are interspersed throughout the lecture. Like testing in general, interpolated testing appears to benefit performance on content tests amongst other outcome variables (e.g., mind wandering). While beneficial, adding testing also increases instructional time. In the present investigation we examine one strategy to mitigate the costs of this increase in instructional time in the context of recorded lectures. Specifically, we examine the interaction between increasing the playback speed of a recorded lecture and adding interpolated tests. Results demonstrate that the conjoint effects of these two interventions is largely additive. That is, the benefit of testing was as robust in a normal speed lecture and a lecture that was sped up 1.5x.