6 minute read · Updated October 2026
The idea in one paragraph
Memory fades quickly after you learn something, then more slowly. Hermann Ebbinghaus measured this in the 1880s and it has been confirmed many times since. Each time you successfully recall a fact, it fades more slowly than before. So the efficient moment to review is not straight away, when it is still fresh, and not weeks later, when it is gone, but just as it is starting to slip. Do that a handful of times, with a longer gap each time, and the fact stays for months.
A large review of study techniques by Dunlosky and colleagues in 2013 rated spreading practice over time as one of only two “high utility” methods. The other was testing yourself. Spaced repetition with flashcards does both at once.
Why cramming feels better and works worse
Going over the same material five times in one evening feels productive, because by the fifth pass everything is familiar. That familiarity is short-term. A week later most of it is gone. Five reviews spread over three weeks take the same total time and leave far more behind. The catch is that spaced reviews feel harder, because you are pulling things back from the edge of forgetting. That difficulty is the method working.
The five-box method
You do not need software to do this. The classic paper version uses five boxes, and it is the same logic most apps use.
- Every new card starts in box 1. Box 1 is reviewed every day.
- Get a card right and it moves up one box. Each box is reviewed less often than the one before.
- Get a card wrong and it goes back to box 1, whichever box it was in.
- Each day, review only the boxes that are due.
A workable set of gaps is one day, three days, seven days, sixteen days and thirty-five days. A card you know well is seen five times over about two months and then leaves you alone. A card you keep missing stays in front of you every day until it sticks.
How to start today
- Start early. The method needs weeks to work. Starting three days before an exam is cramming with extra steps.
- Add cards as you go, a few after each lecture or reading, not one giant deck at the end.
- Do the due cards every day. Ten minutes daily beats an hour on Sunday. Skipped days pile up quickly.
- Say the answer before you flip. If you could not say it, it was wrong, even if it looked familiar when you saw it.
- Be honest when you grade yourself. “Nearly” goes back to box 1.
Mistakes that waste it
- Cards that are too big. If an answer has three parts you will half-know it forever. One idea per card. See how to make flashcards that work.
- Memorising what you never understood. Spaced repetition keeps knowledge; it does not create understanding. Learn the idea first.
- Only using it for definitions. It works just as well for the steps of a method, when a formula applies, and common mistakes.
- Too many new cards at once. Every new card creates reviews for weeks. Twenty a day is plenty for most courses.
Where an app helps
The boxes are simple, but keeping track of which card is due on which day gets tedious past a few hundred cards. That bookkeeping is what apps are for. Audiken’s flashcards use the five boxes and the gaps described above, write the cards from your own lectures and files, and show you only what is due today. If you already use Anki, you can export the cards to it.
More guides
- How to ask permission to record a lecture
- How to take meeting notes people use
- How to make flashcards that work
- How to take notes in a fast lecture
- How to write a follow-up email after a meeting
Let the schedule run itself
Audiken transcribes what is said, explains things as they come up, and builds notes, documents and study material from your own files. Accounts are opening a few at a time.
Accounts are opening a few at a time. No card needed, and one email when yours is ready.