Spaced repetition, explained
You learn a shortcut on Monday and it is gone by Friday. That is not a character flaw; it is the normal shape of forgetting. Spaced repetition works with that shape instead of against it.
The forgetting curve
In 1885 Hermann Ebbinghaus memorised lists of nonsense syllables and measured how quickly they faded. Recall dropped steeply in the first day, then levelled off. Later research, including large reviews of spacing studies by Nicholas Cepeda and colleagues, found the same pattern: reviewing after a gap beats cramming the same number of repetitions into one sitting.
Drag the review days below. Each review resets recall to the top, and because the memory is now sturdier, the next drop is gentler. Put reviews too close together and you waste effort; wait too long and you are relearning from scratch.
With these reviews, modelled recall on day 30: 61%. Never reviewed: 0%.
A simplified exponential model in the spirit of Ebbinghaus’s forgetting curve, for illustration only; real forgetting rates vary by person and by shortcut.
Boxes instead of algorithms
Sebastian Leitner turned the idea into a shoebox of flashcards in 1972. Cards you know move to a box you open less often. Cards you miss go back to the front. No maths needed, and it is exactly what the trainer on this site does, with five boxes reviewed every 1, 3, 7, 16 and 35 days.
Step one card through the boxes and watch what a single miss does.
- Box 1every 1 day
- Box 2every 3 days
- Box 3every 7 days
- Box 4every 16 days
- Box 5every 35 days
A new card (Ctrl+Z) waits outside the boxes. Answer it:
Why shortcuts suit it so well
A shortcut is a small, testable fact with an instant right-or-wrong answer, the ideal flashcard. And because the trainer asks you to press the keys rather than recognise them, each review rehearses the motor pattern you need in the real app. Psychologists call this the testing effect: retrieving an answer strengthens memory more than seeing it again.
Spacing works on ideas too: watch ahaboo’s narrated explainer on why the Moon has phases, revisit it three days later, and notice how much less you have to rebuild.
How to use it here
- Pick the app you use most and run one round. Start with ten shortcuts, not a hundred.
- Come back tomorrow and open Daily review. It only shows shortcuts that are due.
- When a shortcut reaches box 5, use it in real work. That is the final review.
Questions
What is spaced repetition?
Spaced repetition is a study method where you review material at increasing intervals, just as you are about to forget it. Each successful recall makes the memory more durable, so the next gap can be longer.
Who discovered the forgetting curve?
The German psychologist Hermann Ebbinghaus described it in his 1885 book Über das Gedächtnis (Memory), after testing himself on lists of nonsense syllables.
What is the Leitner system?
A paper flashcard method published by Sebastian Leitner in 1972. Cards move up a box when you answer correctly and back to the first box when you miss; higher boxes are reviewed less often.
How often should I review keyboard shortcuts?
A few minutes a day is enough. MasterShortcuts schedules each shortcut at 1, 3, 7, 16 and 35 days after correct answers, and brings misses back the next day.