What is the Leitner system?
The Leitner system is a flashcard schedule described by Sebastian Leitner. You do not review every card every day. Cards you already know wait in a later box. Cards you miss come back tomorrow. That is spaced repetition in paper form. A fuller schedule is in the spaced repetition guide.
How many boxes, and when do you open them?
- Box 1. Every study day. New cards and missed cards live here.
- Box 2. Every two or three days.
- Box 3. About once a week.
- Boxes 4 and 5, if you use them. Less often still. Three boxes are enough to start.
The six-step Leitner workflow
- Write one fact per card. A question on the front. A short answer on the back. A paragraph is a note, not a card.
- Start every card in box 1. Do not sort new cards into later boxes because they felt easy while you copied them.
- Answer before you flip. Say or write the answer. Flipping first turns the session into reading.
- Move recalled cards forward. A correct answer from box 1 goes to box 2. A correct answer from box 2 goes to box 3.
- Return missed cards to box 1. A miss from box 3 does not stay in box 3. It comes back tomorrow.
- Open boxes on a schedule. Daily for box 1. Less often for later boxes. Stop when the day’s boxes are empty, not when you feel finished.
What does one session look like?
Front: What do the light reactions produce?
You say: ATP and NADPH.
Back matches: move the card from box 1 to box 2.
You say only “energy”: the card stays in, or returns to, box 1.
What mistakes keep every card in box 1?
- Putting a whole definition you cannot say on the front.
- Calling a card correct because the back looked familiar after you flipped.
- Leaving a missed card in a later box “because you knew it last week.”
- Reviewing all boxes every day, which removes the spacing.
How can an app keep the boxes?
Make the same one-question cards in Feynman AI and let a spaced schedule decide the next time you see each one. The rule does not change: answer first, then check. A short sitting fits the study session planner or a 25-minute Pomodoro.
Frequently asked questions
What is the Leitner system?
The Leitner system, from Sebastian Leitner, sorts flashcards into boxes. Cards you recall move to a box you see less often. Cards you miss return to the box you see every day.
How many Leitner boxes do you need?
Three to five boxes are enough. Box 1 is daily. Each later box is opened less often.
Is the Leitner system the same as spaced repetition?
It is a simple paper form of spaced repetition. Apps can schedule the same idea card by card. The rule is the same: recalled cards wait longer, missed cards come back soon.
What should go on a Leitner card?
One question you can answer from memory, and a short check on the back. A whole paragraph on the front is a note, not a card.
Sources
- Leitner, Sebastian. So lernt man lernen. The box schedule for flashcards.
- Karpicke and Roediger, 2008. The critical importance of retrieval for learning.
Related guides
Answer the card before you sort it
The box only records whether you produced the answer.
Open the study session planner