Spaced repetition: revise less, remember more
The science of revisiting content at exactly the right time
The forgetting curve — first described by Hermann Ebbinghaus — shows that we forget around 70% of new information within 24 hours if we don't revisit it. The good news: each time you review something just before you'd forget it, the forgetting slows dramatically. This is spaced repetition.
How forgetting works (without review)
The optimal review schedule
A simple spaced schedule works well for most students: review new material after 1 day, then after 3 days, then 1 week, then 2 weeks, then 1 month. Each successful review extends the interval. Each failed retrieval resets it.
This app's Review queue is built around spaced repetition. When you mark a point as 'weak', it stays in your queue until you've confidently retrieved it. Points you already know don't take up your revision time.
How to apply spaced repetition without software
- Divide your notes into topics. Date each topic the first time you study it
- After 1 day, test yourself on it without looking. Make a note of what you forgot
- Review again on day 3, day 7, day 14, day 30
- If you nail a review session, skip to the next interval. If you struggle, go back to day 1
- Don't start the next topic until you've scheduled the first review for the current one
Doing 20 minutes of spaced review daily beats a 4-hour cramming session the night before. Cramming works for the exam but the knowledge is gone within a week.