Spaced Repetition

Review information at increasing intervals to flatten the forgetting curve and build permanent memory.

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Spaced repetition is a learning technique where you review information at gradually increasing intervals. It is based on the forgetting curve — the observation that memory decays predictably over time without review. By reviewing material right before you would forget it, you reset the curve and slow future decay. Over time, this lets you remember almost anything almost permanently, with surprisingly little ongoing effort.

How Spaced Repetition Works

Without review, we forget most of what we learn within days — this is the forgetting curve. Each review resets the curve and makes it decay more slowly, so you can wait longer before the next review. By reviewing at expanding intervals (1 day, 3 days, 1 week, 2 weeks, 1 month), you efficiently build long-term memory. The key: review too soon and you waste time; review too late and you relearn. Spaced repetition hits the sweet spot — right before you would forget.

How to Use Spaced Repetition

  1. 1
    Break material into reviewable units

    Each fact, concept, or question becomes one card or item.

  2. 2
    Review after 1 day

    Your first review should happen the day after initial learning.

  3. 3
    Extend the interval if recalled easily

    Next review in 3 days, then 1 week, then 2 weeks, then 1 month.

  4. 4
    Reset the interval if forgotten

    If you could not recall, study it again and review tomorrow.

  5. 5
    Use spaced repetition software

    Apps like Anki handle scheduling automatically. You just study and rate recall.

  6. 6
    Review daily in short sessions

    10–20 minutes daily beats long weekly sessions. Consistency is essential.

Best Practices

  • Combine with active recall

    Each review must be an active retrieval, not passive re-reading. This combination is the most powerful study method known.

  • Keep cards atomic

    One concept per card. Complex cards are hard to schedule and review.

  • Be honest about recall

    Rate "easy" only if you knew it instantly. Over-rating leads to forgetting.

  • Make your own cards

    Creating cards is itself active learning. Pre-made decks are less effective.

Common Mistakes

  • Cramming reviews in one day

    Spaced repetition requires spacing. Batching defeats the purpose.

  • Making cards too complex

    Cards with multiple facts are hard to rate. Keep each card to one idea.

  • Skipping days

    Missing days lets reviews pile up and breaks the habit. Even 5 minutes daily is better than skipping.

Frequently Asked Questions

What is the best spaced repetition schedule?
A common effective schedule: 1 day, 3 days, 1 week, 2 weeks, 1 month, 3 months. Apps like Anki use algorithms (SM-2) that adjust intervals based on how easily you recalled each item, which is more efficient than fixed schedules.
Do I need an app for spaced repetition?
No, but it helps. You can use a calendar or paper system. Apps (Anki, Quizlet) automate scheduling so you just show up and study. For large volumes of material, an app is strongly recommended.
How much time does spaced repetition take?
Surprisingly little. Once set up, daily reviews take 10–20 minutes for most learners. The time investment is front-loaded (creating cards), and the payoff is long-term retention with minimal ongoing effort.

Related Resources

Active RecallRetrieval PracticeFlashcards

Put This Into Practice

Create a personalized AI learning path that applies these techniques with lessons, exercises, and assessments.

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