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Become a better student · Module 3: Revision that works

Flashcards that actually work

Flashcards are one of the best revision tools there is, if you use them to test yourself rather than to re-read.

Written by the Brainhub Editorial Team Cites published research Updated 13 Oct 2026 6 min read

The course unlocks one lesson at a time. You can read this now, but it only counts once you’ve finished Stop re-reading.

Key takeaways

1. Make them make you think

A good flashcard asks a question you have to answer from memory: “What are the products of photosynthesis?” rather than a heading with a paragraph of notes on the back. Keep one idea per card, and write the question in your own words.

2. Don’t drop cards too soon

It’s tempting to remove a card once you get it right. In a well-known study, students who kept practising retrieval of items they had already recalled remembered far more a week later than students who dropped those items from practice.[1]

Getting it right once isn’t the finish line. Recalling it again, after a gap, is what makes it last.

3. One big stack beats small piles

In another study, students learned vocabulary from one large stack of cards or from several small stacks studied intensively. The large stack spaced each card out naturally and worked better for 90% of students, even though most thought the small stacks felt more effective.[2]

If you can see the answer coming, the card is too easy, or too soon.

4. The box system

A simple box system, often called the Leitner system, automates spacing. Cards you know move to boxes you check less often; cards you miss go back to the start.

Box
Check it
What happens
Box 1
Every day
New cards and cards you got wrong
Box 2
Every 3 days
Right once: move here
Box 3
Every week
Right again: move here
Box 4
Every 2 weeks
Right again: move here. Wrong at any point: back to Box 1

For parents: Offer to be the quizmaster. Read the question, and wait for a full answer before turning the card.

Try it now

Test yourself on this page

Answer in your head first, then check.

  1. 1. What should you do before flipping a card?

  2. 2. Why shouldn’t you drop a card after one correct answer?

  3. 3. In the box system, where does a card go if you get it wrong?

Your next steps

  • Turn one page of notes into 10 question-and-answer cards.
  • Set up four boxes or envelopes labelled 1 to 4.
  • Do Box 1 every day this week.

Finished this lesson?

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Sources

  1. Karpicke, J. D. and Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968. doi:10.1126/science.1152408
  2. Kornell, N. (2009). Optimising learning using flashcards: spacing is more effective than cramming. Applied Cognitive Psychology, 23(9), 1297–1317. doi:10.1002/acp.1537

This guide is general study advice. Every student is different. A teacher can help you work out what fits.