How to make flashcards that actually work
Flashcards are one of the best study tools there is, and most people use them in a way that throws away half the benefit. The problem is rarely the idea. It is how the cards are written, and what you do with the stack.
Why flashcards work at all
A flashcard forces you to pull an answer out of memory before you see it, and that act of retrieving is what makes it stick. Students who took practice recall tests on a passage remembered far more of it a week later than students who spent the same time re-reading it, even though the re-readers felt more confident (Roediger & Karpicke, Psychological Science, 2006). A card only works if you genuinely try to answer before you flip it.
Six rules for the cards themselves
- One fact per card. "Causes of World War One" is a chapter, not a card. Split it into cards you can answer in a few seconds.
- Ask a real question. "Mitochondria" on the front tells you nothing. "Which organelle releases energy from glucose?" makes you retrieve.
- Write it in your own words. Copying a sentence from the textbook lets you recognise it without understanding it.
- Answer out loud or on paper before flipping. "I kind of knew that" is the most expensive phrase in revision.
- Add a picture or a diagram where the topic is visual, like a labelled cell or a graph shape.
- Make cards from your mistakes. Every question you get wrong in a past paper becomes a card that night.
Keep the stack big and spaced
This is the part almost everyone gets wrong. It feels efficient to study a small pile until you know it, then move on. In a set of flashcard experiments, studying one large stack, where each card comes round less often, was more effective than studying the same cards as four small stacks, and spacing beat cramming the day before the test (Kornell, Applied Cognitive Psychology, 2009). The small stack felt better. The big one worked better.
The reason is the same one behind all spaced practice: a meta-analysis of hundreds of experiments found that spacing study apart beats massing it together for long-term retention (Cepeda, Pashler, Vul, Wixted & Rohrer, Psychological Bulletin, 2006). A little forgetting between reviews makes the next retrieval harder, and that effort is what builds the memory.
How often to review
- Cards you got wrong come back the same day, then the next day.
- Cards you got right wait longer each time: a few days, then a week, then longer.
- Don't drop a card because you got it right once. Push it further out instead.
Doing that by hand with paper cards means boxes and a system (the Leitner method is the classic one). An app that uses spaced repetition does the scheduling for you: it shows you each card just as you are about to forget it. We explain the idea in how spaced repetition works.
Three habits to drop
- Flipping before answering. That is reading, not testing.
- Making cards the night before. Making them is useful; making them instead of reviewing them is not.
- Only reviewing the easy pile. The cards you dread are the ones doing the work.
If you learn differently, the same rules apply, with a few extras that help: short sessions, a timer, fonts and spacing that make the card easy to read. Parents of children with ADHD or dyslexia will find more in the best flashcard app for ADHD and dyslexia on Versed Learn.
Versed Learn's flashcards are free, schedule themselves with spaced repetition and work in guest mode, no account needed to start (an account only adds sync across devices). Make a deck at learn.versedapps.com.