Spaced repetition
Spaced repetition is a study method where you review material at growing gaps in time, just before you would forget it. Each review pushes the next one further out, so the facts move into long-term memory instead of fading away after a day.
In more detail
Right after you learn something, you start forgetting it fast. By the next day a big chunk is already gone. Spaced repetition fights that. You review at the moment you are about to forget, which resets the clock and makes the memory stick longer each time.
The gaps grow as you go. Maybe you review after one day, then three days, then a week, then two weeks. Stuff you keep getting wrong comes back sooner. Stuff you know well comes back later. That way you spend your time on the things that actually need it.
It beats cramming because cramming only holds for a few hours. Spreading the same reviews over days or weeks gives you way better recall when the exam comes.
Example
Mara has a biology exam in three weeks. Instead of one long night, she goes through her flashcards for 15 minutes most days. The cards she nails keep coming back less often, and the three terms she always mix up keep popping up until they stick.
How to use it
- 1
Break your material into small questions or cards, one idea each.
- 2
Test yourself by trying to recall the answer before you check it.
- 3
Review again after one day, then space the next review further out each time you get it right.
- 4
Bring the cards you got wrong back sooner and review them more.
- 5
Keep short sessions going over days and weeks instead of one long cram.
How StudyPDF does this
Upload your notes or slides and StudyPDF turns them into flashcards and quizzes you can review over time. It tracks which ideas you keep getting wrong and drills those more, so your reviews land on the stuff you actually forget.
See also
- TermActive recall
- TermForgetting curve
- TermLeitner system
- TermDistributed practice
- AnswerHow do you use Anki?
- AlternativesThe best Anki alternatives in 2026
- ComparisonAnki vs Brainscape: which flashcard app is better?
- ComparisonAnki vs RemNote: which is better for flashcards and notes?
- TermRetroactive interference
- TemplateIndex card template: free printable study cards
- StudyPDFAI Flashcard Maker
Common questions
How is spaced repetition different from just rereading my notes?
Rereading feels easy but it does not test your memory, so it fades fast. Spaced repetition makes you recall the answer yourself, which is harder and far stickier. The growing gaps also mean you hit each fact right when you are about to lose it, instead of at random.
How long should the gaps between reviews be?
A common pattern is one day, then three days, then a week, then two weeks, getting longer each time you remember well. There is no perfect number. The rule is simple: if you got it right, wait longer next time; if you got it wrong, review it again soon.
Put it to work on your own course
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