Spaced Repetition
Definition
Spaced repetition is a learning technique where you review information at gradually increasing intervals. Instead of cramming everything into one session, you revisit material just before you are likely to forget it. Each successful review pushes the next one further into the future. The method is based on the spacing effect, first documented by psychologist Hermann Ebbinghaus in 1885, who showed that memory decays predictably over time but can be maintained with strategically timed review.
Why It Matters
Most of what you learn at work disappears within days if you do not revisit it. A workshop, a book, a training session: without reinforcement, the majority fades. Spaced repetition is the most efficient way to counteract that decay. Instead of spending hours rereading material, you spend minutes reviewing it at the right moments. For anyone who needs to build and maintain expertise over time, whether in a new role, a technical domain, or a foreign language, spaced repetition turns one-time learning into lasting knowledge with minimal ongoing effort.
Example
A junior analyst learns a new financial modeling framework during onboarding. Instead of hoping she will remember it, she creates a few flashcards with the key concepts. She reviews them the next day, then three days later, then a week later, then two weeks later. After a month, the intervals are measured in weeks and the total review time adds up to less than 30 minutes. Three months in, the framework feels second nature.
What It Is Not
Spaced repetition is not just flashcards, although flashcards are the most common tool. It is a scheduling principle that can apply to any form of review. And it is not a substitute for understanding. Repeating something you never understood in the first place just produces confident ignorance. It works best when combined with active recall, where you genuinely try to retrieve the answer before checking it.
Related Concepts
Active Recall - the retrieval effort that makes each spaced repetition session effective
Cognitive Load - spaced repetition reduces long-term cognitive load by moving knowledge from fragile short-term memory into durable long-term storage
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