The art of thinking · 7 · Brain and learning
Spacing effect
Also known as: Distributed practice effect, Spaced repetition effect, Spacing effect (memory)
German: Spacing-Effekt
In memory research, the spacing effect is the finding that information studied in sessions spread out over time is retained better than the same amount of study massed into a single session; Hermann Ebbinghaus reported it in Über das Gedächtnis (1885).
- Cognitive psychology
- Learning
In one sentence
The spacing effect: study spread out over time is retained better than the same study massed into one session (Ebbinghaus, 1885).
Example
A technician who reviews a new changeover procedure briefly on three days recalls it better a month later than one who reads it three times in one evening.
What the research shows
Hermann Ebbinghaus, who memorized lists of nonsense syllables in his own experiments, observed in Über das Gedächtnis (1885) that repetitions distributed over several days were more effective than the same number of repetitions in one session. Nicholas J. Cepeda and colleagues (2006) synthesized hundreds of experiments on verbal recall: spaced study produced better retention than massed study, and the best gap between sessions grew with the time over which the material had to be remembered.
Evidence status
The spacing effect is one of the most robust findings of memory research, replicated with many materials, ages and settings. How large the benefit is, and which gap is best, depends on the material and on how long it must be retained.
How it applies
- Training and documentation: Material that readers must remember — rarely performed procedures, safety rules — is better supported by spaced refreshers than by one long training session.
- For writers: Returning to a draft after a pause shows what was understood and what only felt familiar (see metacognition).
External references
- Ebbinghaus, H. (1885). Über das Gedächtnis: Untersuchungen zur experimentellen Psychologie. Leipzig: Duncker & Humblot.
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380. https://doi.org/10.1037/0033-2909.132.3.354
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