Do I need an app to do spaced repetition?

No. The underlying habit is review at expanding intervals. Apps automate scheduling for hundreds or thousands of cards, but a manual 1-3-7-14-30 schedule works for small sets.

How long should each review take?

Most effective reviews are short and frequent. Five to twenty minutes is typical. Long, infrequent reviews lose to short, frequent ones.

What is the spacing effect?

The spacing effect is the finding that information is retained better when learning sessions are spread over time, compared to massed study in a single sitting.

Can spaced repetition replace re-reading?

For factual recall, yes. For comprehension and insight, re-reading and writing still beat pure recall practice. Use both.

Definition

What is spaced repetition?

Spaced repetition is a learning technique that schedules reviews of a piece of information at increasing intervals, with each successful recall pushing the next review further out. The goal is to interrupt the natural forgetting curve at the latest possible moment so each review costs less effort than the last.

Last updated 2026-05-25 - scrollandlearn team

The forgetting curve, briefly

Hermann Ebbinghaus mapped how quickly we forget new information in the late 1800s. Without reinforcement, retention drops sharply within hours and days. Spaced repetition exploits the spacing effect: each well-timed review flattens the curve.

~75%

of new information forgotten within 48 hours without review

Source: Ebbinghaus's forgetting curve research

Typical interval schedules

Leitner: 5 boxes with intervals of 1, 2, 4, 8, and 16+ days.
SuperMemo SM-2: dynamic intervals based on recall quality.
Anki FSRS: ML-based scheduling tuned per user history.
Manual 1-3-7-14-30: a simple human-friendly schedule for handbook reviews.

Where spaced repetition helps and where it does not

Use case	Good fit?	Why
Language vocabulary	Yes	Discrete units, clear right answer
Medical or legal facts	Yes	Volume of memorization, high cost of recall failure
Software API names	Partial	Faster than docs once committed
Skill practice (writing, design)	No	Practice needs production, not recall
Soft knowledge from podcasts	Partial	Review captures, not flashcards

Spaced repetition for handbook readers

You do not need a flashcard deck to benefit. A weekly review where you skim the past week's lessons, a monthly review of the past month, and a quarterly archive sweep produce a similar effect with less overhead. The point is structured revisiting at expanding intervals.

scrollandlearn keeps your captures organized by chapter and time, so a weekly review is a five-minute scroll, not a project.

Frequently asked questions

Do I need an app to do spaced repetition?: No. The underlying habit is review at expanding intervals. Apps automate scheduling for hundreds or thousands of cards, but a manual 1-3-7-14-30 schedule works for small sets.
How long should each review take?: Most effective reviews are short and frequent. Five to twenty minutes is typical. Long, infrequent reviews lose to short, frequent ones.
What is the spacing effect?: The spacing effect is the finding that information is retained better when learning sessions are spread over time, compared to massed study in a single sitting.
Can spaced repetition replace re-reading?: For factual recall, yes. For comprehension and insight, re-reading and writing still beat pure recall practice. Use both.

Make weekly review effortless

scrollandlearn groups every capture into chapters with timestamps, so spaced review is a five-minute scroll instead of a project.

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