Definition
Spaced repetition is the practice of reviewing material at increasing intervals so that each review happens just as the memory is about to fade.
Why it matters
Spacing turns forgetting from a threat into a teacher: the small effort of remembering against growing intervals produces dramatically more durable memory.
Scientific basis
The spacing effect is one of the most robust findings in learning science; review after a delay consistently outperforms review immediately after learning.
How to apply it
- Schedule reviews at growing intervals: one day, three days, a week, two weeks, a month.
- Use an SRS app or paper box system to track what is due.
- Allow some forgetting to happen between sessions; the struggle is the mechanism.
Common mistakes
- Reviewing only on the day before an exam.
- Re-doing the entire deck every session instead of trusting the schedule.
- Conflating difficulty with failure and re-scheduling too aggressively.
Examples
- Medical students using Anki to retain thousands of facts across multi-year programmes.
- Language learners spacing vocabulary review over weeks and months.
Related concepts
- Massed Practice (contrasts with)
Spaced repetition directly opposes massed practice and produces much stronger retention. - Desirable Difficulties (is an instance of)
Spacing is a paradigmatic desirable difficulty.
Where it shows up
Domains: language-learning, test-prep, student-learning. Appears in the Practice & Spacing cluster alongside 3 other concepts.
Source books
- Make It Stick: Brown, Roediger & McDaniel
- Learning How to Learn: Barbara Oakley
- Ultralearning: Scott Young
Articles that use this concept (6)
- The Forgetting Curve, Explained Without Jargon: forgetting curve
- What Is Spaced Repetition (And Why It Works): spaced repetition
- Spaced Repetition vs. Cramming: A Real Comparison: spaced repetition vs cramming
- Combine Spacing and Depth: spacing and depth
- Spaced Repetition for Mastery, Not Just Memory: spaced repetition mastery
- Spaced Repetition: The Complete Guide: spaced repetition guide