What is spaced repetition?

The forgetting curve

Learn something new and your memory of it decays over the following hours and days — the classic “forgetting curve.” But each time you successfully recall the item, the curve flattens: you forget more slowly, and the next review can wait longer. Spaced repetition is simply the practice of timing reviews to ride that curve.

Why spacing beats cramming

Studying the same word five times in one sitting produces a warm feeling of familiarity and very little durable memory. Spreading those five reviews across days — the spacing effect — forces your brain to reconstruct the memory each time, which is exactly what makes it last. Combine that with active recall (retrieving the answer, not just re-reading it) and you have the two most evidence-backed study techniques working together.

How to use it

• Test, don’t review. Try to produce the word before you check it.
• Space out the wins. Push easy words to longer intervals; see hard ones again soon.
• Be consistent. A short daily session beats a long weekly one — the schedule only works if you show up.

You can run this by hand with paper flashcards (the Leitner box) but it gets unwieldy fast. Software does the scheduling for you — and the algorithm doing it matters.

How 10 Words automates it

10 Words schedules every word with FSRS, a modern spaced-repetition algorithm that models your personal memory and shows each word right before you’re about to forget it. You just solve today’s ten — the timing is handled for you, and because each word is a fill-in-the-blank sentence, every review is also active recall in context.