Spaced repetition: what it is and how to use it (with a simple schedule)
If you've ever crammed for a test and forgotten everything a week later, you've met the forgetting curve. Spaced repetition is the cure: instead of studying something many times in one go, you review it a few times, with growing gaps in between.
Why spacing works
Memories fade over time, fast at first and then more slowly. Each time you review something just as it's starting to fade, the memory gets stronger – and it fades more slowly afterwards. So each gap between reviews can be longer than the last.
Spacing is one of the most reliable findings in learning research. A large review by Nicholas Cepeda and colleagues, combining hundreds of experiments, found that spreading out study sessions leads to better long-term memory than packing them together. And when Nate Kornell compared flashcards studied in one big deck (more spacing) with small decks (less spacing), the big deck won for most people – even though they felt the small decks worked better.
A simple review schedule
You don't need to be exact. A schedule like this works well for most material:
| Review | When |
|---|---|
| 1st | The same day you learn it |
| 2nd | 1–2 days later |
| 3rd | About a week later |
| 4th | About two to three weeks later |
| 5th | About a month later, or before the test |
Each review should be active: test yourself rather than re-read. What active recall is.
The Leitner box method
Sebastian Leitner, a German science journalist, described a simple way to space flashcards using a few boxes:
- Put all new cards in Box 1.
- Review Box 1 every day, Box 2 every few days, Box 3 once a week (and so on, if you have more boxes).
- When you answer a card correctly, move it up one box – you'll see it less often.
- When you get a card wrong, move it back to Box 1 – you'll see it more often.
The cards you find hard automatically come up more often; the ones you know well wait longer. Many flashcard apps use the same idea.
Tips
- Start early. Spacing needs days, so it can't be squeezed into the night before a test.
- Mix topics in each review session. Why mixing helps.
- Don't stop too soon. Getting something right once isn't the same as knowing it for good.
- Keep it short. Ten minutes of daily review beats an hour once a week.
Spaced practice, built in
TONEC STUDY's daily tasks give you a few questions every day, so practice is naturally spread out. With Premium, the questions you got wrong come back until you get them right, and revision sessions start with your weakest questions first.
The research
- 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).
- Kornell, N. (2009). Optimising learning using flashcards: Spacing is more effective than cramming. Applied Cognitive Psychology, 23(9).