- Title: Spacing and Interleaving Effects Require Distinct Theoretical Bases: a Systematic Review Testing the Cognitive Load and Discriminative-Contrast Hypotheses
- Authors: Chen, Pass and Sweller
- Access the original paper here
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Paper summary
This paper analyzes the effects of spaced and interleaved practice on learning, arguing that these two strategies should be distinguished and understood as separate phenomena. The researchers suggest that spaced practice, where learning sessions are separated by periods of rest, works by allowing depleted working memory resources to recover, while interleaved practice, where different topics are mixed together during learning, relies on a discriminative-contrast effect, which helps learners differentiate between similar concepts. The paper provides a systematic review of literature to support these hypotheses, presenting evidence for the spacing effect in studies that include rest periods and for the interleaving effect in studies that do not. Finally, the authors highlight the importance of understanding the distinct mechanisms behind these two learning strategies to guide instructional design and maximize student learning.
What are the key implications for teachers in the classroom?
- Spaced practice, which involves alternating periods of learning with periods of rest, can enhance student learning. This effect may occur because rest allows students to restore depleted working memory resources. Spaced practice can be implemented by distributing learning sessions across multiple days or months, or by inserting rest periods between learning sessions.
- When implementing spaced practice, the rest periods should not be filled with other learning activities. The rest periods should allow students to disengage from deliberate learning so that their working memory resources can recover. Examples of appropriate rest-from-deliberate-learning activities include sleeping, taking breaks, playing, or reading non-targeted passages.
- The length of the rest periods in spaced practice can vary. The spacing effect has been observed with rest periods ranging from 30 seconds to a few days.
- Interleaved practice, which involves alternating practice of different skills, can also improve learning. This effect is thought to occur because interleaving helps students discriminate between similar concepts or topics. Interleaving can be implemented by shuffling different topics together during practice or by inserting lags (i.e., intervening topics) between two targeted topics.
- Interleaving is most effective when the interleaved topics are similar and require students to learn to discriminate between them. When topics are very dissimilar, interleaving may not be effective.
- Teachers should consider the cognitive demands of the tasks they are teaching when deciding whether to use spaced or interleaved practice. Spaced practice is more appropriate when learners need to mentally rest from learning, while interleaved practice is more appropriate when learners need to discriminate between similar instructional areas.
- Further research is needed to determine the optimal parameters for spaced and interleaved practice, such as the length of rest periods and the level of similarity between interleaved topics.
This systematic review focused on analyzing empirical data from research studies on spaced and interleaved practice. It did not cover opinions or anecdotal evidence.
Quote
The data of this review suggest that the spacing effect needs a rest-from-deliberate-learning period between learning episodes
