Leitner system
The Leitner system is a spaced-repetition method for flashcards that sorts cards into numbered boxes. Cards you answer correctly move up to a box you review less often, while cards you miss drop back to box 1 for daily practice.
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In more detail
The Leitner system makes spaced repetition physical and simple. Every card lives in a box, and the box number sets how often you see it. Right answers earn a card a longer break, wrong answers send it back to the front, so your time naturally pools around the material you keep getting wrong.
A common mix-up: the boxes are not difficulty labels you assign by hand. A card's box is decided only by your last few attempts. Box 1 might be reviewed daily, box 2 every two days, box 3 weekly, and so on. The exact intervals are yours to set, as long as higher boxes are spaced further apart.
Example
You are studying the Krebs cycle from your biochemistry lecture. The card asking which enzyme converts citrate to isocitrate keeps tripping you up, so it stays in box 1 and you see it every day. The card naming the cycle's end product moves to box 3 after three clean recalls, and you only review it once a week.
How to use it
- 1
Set up 3 to 5 boxes and put every new card in box 1.
- 2
Each session, review the boxes that are due that day.
- 3
If you answer a card correctly, move it up one box.
- 4
If you miss a card, send it straight back to box 1.
- 5
Space the boxes wider apart as the number rises, so higher boxes come up less often.
How StudyPDF does this
StudyPDF turns your uploaded lectures and PDFs into grounded flashcards, and every rating you give a card updates that concept's mastery with time decay. That is the Leitner idea automated: weak concepts resurface for targeted practice while ones you have nailed fade back.
See also
- TermSpaced repetition
- TermFlashcard
- TermAnki export
- TermActive recall
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Common questions
How many boxes should a Leitner system have?
Three to five boxes works for most students. Three is easy to manage by hand, while five lets you stretch the gaps wider for material you know well. There is no fixed rule, so pick the number you will actually keep up with.
How often should I review each Leitner box?
Review box 1 daily, then space each higher box further apart, for example every two days, then weekly, then every two weeks. The exact intervals are flexible. The only rule is that higher boxes get longer gaps than lower ones.
Put it to work on your own course
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