Spaced repetition explained — why timing matters for memory

Spaced repetition is a revision technique based on reviewing material at increasing intervals over time — rather than cramming it all in one sitting — to build much stronger, longer-lasting memory.

The idea behind it

Memory naturally fades over time (the 'forgetting curve'), but each time you successfully recall something just as you're about to forget it, the memory is strengthened and the next forgetting curve becomes flatter — meaning you can wait longer before reviewing it again. Spacing reviews out, with growing gaps, takes advantage of this.

How it compares to cramming

Cramming can work for short-term recall (like the next day's test) but the information fades fast afterwards. Spaced repetition takes more total time upfront but builds memory that lasts weeks, months or years — far more useful for cumulative subjects and final exams.

How to use it

• Review new material soon after learning it (e.g. the next day)
• Then again after a few days
• Then a week, then a few weeks, growing the gap each time
• Combine with active recall — testing yourself, not just re-reading — for the best results

Our free active recall study sheet and revision planners help you put this into practice.