Distributed practice is considered a better learning strategy than massed practice. This is also known as the spacing effect. Learners space their learning sessions by leaving periods of rest in between their learning sessions during distributed practice, whereas learners cram their learning sessions without rest in massed practice. Researchers suggest that these periods of rest between learning sessions make retrieving information more effortful in subsequent learning sessions because of forgetting. Therefore, the greater effort in retrieving information in distributed practice enhances learning performance. Recently, Chen, Castro-Alonso, Paas, and Sweller (2017) propose working memory resource depletion as an explanation for the spacing effect. They hypothesized that working memory resource is depleted during massed practice resulting in poorer learning performances.
The authors tested the hypothesis in two experiments by comparing the working memory test performances of learners after distributed practice and massed practice. Results of both experiments supported the spacing effect in which learners achieved better learning performances after distributed practice. In addition, learners scored lower on working memory test after massed practice than after distributed practice. In Experiment Two, the hypothesis of working memory resource depletion was further supported by the higher perceived levels of difficulty of the working memory task after massed practice than after distributed practice. The results of the study supported their hypothesis and suggest that the spacing effect is associated with the depletion of working memory resources.
Besides showing that working memory resource depletes after massed practice, results of this study advocate a reevaluation of cognitive load theory’s assumption of fixed working memory capacity. Working memory capacity appears to vary depending on depletion of working memory resource after exerting cognitive effort during learning. Similarly, working memory capacity is optimized following rest periods in between learning sessions, contributing to the spacing effect. Therefore, learners should be advised to space their learning sessions instead of cramming not only because it enhances learning by making retrieval of information more effortful, but also because it optimizes working memory capacity for learning.