Spacing and interleaving, the practice of spreading out the time dedicated to learning and alternating topics while learning, increases the learner's retention of material.
Spacing and Interleaving
SummarySpacing is the process of spreading out study or learning time (Willingham, 2002). Research has proven that "distributing study time over several sessions generally leads to better memory of the information than conducting a single study session" (Willingham, 2002). This is the opposite of "cramming", which involves studying for a long, intense period of time leading up to an exam or due date (Weinstein, 2016).
Interleaving is intertwined with the concept of spacing, and it encourages students to "mix, or interleave, multiple subjects or topics while they study in order to improve their learning" (University of Arizona [UA], 2020). Although more difficult than blocking (focusing on one topic at a time), interleaving creates stronger memory associations and differentiations between topics, leading to more frequent retrievals of memory and better long-term results (UA, 2020).
In both spacing and interleaving, learners "give their mind time to forget so that the brain, in subsequent study sessions, must struggle to recall the information that was learned previously" (UA, 2020).
ApplicationInstructors should encourage students to pursue spacing and interleaving in their study practices. They can also incorporate low-stake, cumulative assessments in the course to encourage students to recall several intertwined topics at once (Webb, 2019). For example, instructors could have students incorporate topics they learned earlier in the semester in a final course project. Another way to incorporate these concepts is to create weekly quizzes that ask about topics learned during that week, the previous week, and three weeks earlier.
- The Interleaving Effect: How Mixing It Up Boosts Learning (article, Scientific American)
- Inspiring Students to Use Interleaving Strategies (video, University of Arizona)
- Spaced Repetition in Learning Theory (video, Osmosis)
- Inspiring Students to Use Spaced Practice (video, University of Arizona)
- Interleaving and Spacing in Practice (article, SecEd)
- Make It Stick: The Science of Successful Learning (book, Brown)