Spaced repetition: how it works and how to schedule your reviews

Spaced repetition means reviewing stuff at longer and longer gaps: a day later, a few days later, a week later. Each review lands just as you're starting to forget, and that makes the memory last far longer than a night of cramming.

You're going to forget, and that's fine

Learn twenty French words today, never look at them again, and most will be gone within a couple of weeks. Hermann Ebbinghaus described this in the 1880s. It's usually called the forgetting curve.

Spaced repetition works with it. Instead of going over everything every day, you review each thing around when you'd forget it, and every successful review pushes the next one further away. The spacing effect has been studied for well over a century and the basic finding keeps holding up.

Why cramming doesn't last

Cramming can get you through tomorrow's test. Then it fades and you're relearning it all for the end-of-year exam.

It also tricks you. Read the same page five times in an hour and it feels familiar, and familiar feels like learned. Spaced reviews feel harder because you've half forgotten. That effort is exactly what makes it stick.

A simple schedule

No need for a precise formula. This works for most people:

• The day after you learn it.
• About three days later.
• About a week later.
• Two or three weeks after that.
• Then roughly once a month until the exam.

Let each card set its own pace

If you get a card right easily, wait longer before seeing it again. Get it wrong and it comes back tomorrow, with its gaps starting from scratch. That's why flashcards and spacing go so well together. You spend your time on the cards you struggle with, not the ones you already know.

Say you've got a biology test on cell structure in two weeks. Day one, make about thirty cards and go through them. Day two, you get twenty right and ten wrong. The twenty can wait a few days, the ten come back tomorrow. By the end of the week you're doing maybe ten or fifteen a day. That's less total time than three hours the night before, and you'll still know it next month.

With Flashcards and the Vocab Trainer

Brainlag's Flashcards tool does the scheduling for you.

• Make a deck per topic, like Cell structure or Spanish unit 3.
• One fact per card, in your own words.
• Answer before you flip, then mark it known or still learning. Don't mark it known if you guessed.
• Come back every day for the cards that are due.
• For languages, do the same with word pairs in the Vocab Trainer. A short example sentence helps a lot.

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