Spaced Repetition
A learning technique where review sessions are spaced out at increasing intervals to exploit the psychological spacing effect for long-term retention.
Spaced repetition is arguably the most evidence-backed learning strategy in all of cognitive science. The principle is counterintuitive: you should review information right before you would forget it, then wait longer before the next review. Each successful recall at a longer interval strengthens the memory trace exponentially. Cramming (massed practice) feels effective but produces fragile memories that decay rapidly. Spaced practice feels harder in the moment but produces memories that last months to years. The technique was formalized by Piotr Wozniak in the SuperMemo algorithm and popularized by apps like Anki. Daily cognitive challenges naturally incorporate spacing — each day brings a new session that builds on skills practiced previously.
Frequently Asked Questions
Why does spaced repetition work better than cramming?
Cramming produces strong short-term recall but weak long-term encoding. Spaced practice forces your brain to reconstruct the memory each time, which strengthens the retrieval pathway. Each successful recall at a longer interval produces a more durable memory trace. Research shows spaced practice produces 50-100% better retention at 30+ days compared to massed practice of the same material.
What is the optimal spacing interval?
It depends on when you need to recall the information. For a test next week, space reviews 1-2 days apart. For long-term retention, start with 1 day, then 3, then 7, then 14, then 30 — roughly doubling each interval. The SuperMemo algorithm optimizes this automatically. Daily puzzle engagement naturally creates spaced practice for cognitive skills.