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Psychology
Why Spaced Repetition Crushes Re-Reading
Forgetting curve, expanding intervals, and Anki
Related Worksheets
Re-reading can feel productive because the material looks familiar while it is in front of you, but familiarity is not the same as recall. After one study session, memory usually drops quickly, especially for facts that were only recognized rather than retrieved. Spaced repetition works better because it brings information back just as it is starting to fade. This makes each review session more effortful, but also more powerful for long-term learning.
Key Facts
- Forgetting curve model: R(t) = e^(-t/S), where R is memory retention and S is memory strength.
- Each successful spaced review increases S, which makes forgetting slower over time.
- Retrieval practice beats passive review because trying to recall strengthens memory pathways.
- Optimal review happens when recall is difficult but still possible, often around 70% to 90% confidence.
- Expanding intervals use short gaps first, then longer gaps: 1 day, 3 days, 7 days, 14 days, 30 days.
- Cramming raises short-term performance, but spaced repetition improves long-term retention and exam transfer.
Vocabulary
- Spaced repetition
- A study method that reviews information at increasing time intervals to strengthen long-term memory.
- Forgetting curve
- A graph showing how memory retention tends to decrease over time when information is not reviewed.
- Retrieval practice
- The act of actively recalling information from memory instead of simply looking at it again.
- Leitner system
- A flashcard method that moves cards to different boxes based on how well you remember them.
- Metacognition
- The ability to judge and monitor your own learning, including knowing what you do and do not understand.
Common Mistakes to Avoid
- Mistaking recognition for memory. Re-reading makes notes look familiar, but an exam usually requires recall without the answer visible.
- Reviewing only right before the test. Cramming can boost performance for a few hours, but it does not create the repeated retrieval needed for durable learning.
- Keeping every flashcard on the same schedule. Easy cards should move to longer intervals, while difficult cards need shorter intervals and better explanations.
- Reviewing too early or too late. If the answer is automatic, the review adds little, but if it is completely forgotten, you may need to relearn instead of strengthen it.
Practice Questions
- 1 A student studies 40 biology terms on Monday and remembers 50% after 2 days. If a spaced review raises retention back to 90%, how many terms can the student recall immediately after review?
- 2 Using the interval pattern 1 day, 3 days, 7 days, and 14 days, list the review dates for a chapter first studied on April 1.
- 3 Explain why a student might feel confident after re-reading a chapter but perform poorly on a closed-book test.