The science of spaced repetition
How memory fades, why testing yourself and spacing your reviews make it last, and what the research shows. Each article cites its sources.
How memory works
- The forgetting curve
What the Ebbinghaus forgetting curve shows, how it was measured and replicated, and how retrieval and spaced reviews slow forgetting.
- The spacing effect
What the spacing effect is, how it differs from spaced repetition, why spreading study over time beats cramming, and how to use it.
- Hermann Ebbinghaus
Who Hermann Ebbinghaus was, how he ran the first memory experiments in 1885, and what he found: the forgetting curve, spacing and overlearning.
Study techniques
- Active recall
What active recall is, why testing yourself beats rereading, what the research shows, and how it works with spaced repetition.
- Retrieval practice
What retrieval practice and the testing effect are, which practice tests work best, the role of feedback, and where the effect is weaker.
- Interleaving
What interleaving is, when mixing related problem types beats practising one at a time, when it does not, and how to use it with flashcards.
- Desirable difficulties
Why study methods that feel harder, such as spacing, self-testing and interleaving, make learning last, and how to tell them from difficulty that only gets in the way.
Spaced repetition in practice
- Spaced repetition schedule
A copyable spaced repetition schedule, what research says about review intervals, how SM-2 and FSRS set them, and how many reviews to expect.
- Does spaced repetition work?
What 140 years of research show about spaced repetition: meta-analyses, long-term and classroom studies, Anki in medical school, and where the evidence is thin.
Memory aids
- Mnemonics
The main types of mnemonic devices with examples, what research says about how well they work, and how to combine them with spaced repetition.
- The memory palace
What a memory palace (method of loci) is, how to build one step by step, what research shows, and where it falls short.