Active recall

There are many ways to "study" a topic: reading your notes, underlining the important parts, watching a video, listening to someone explain it. All of these share one thing in common: they're all passive. Information flows toward you, and you just receive it.

The problem with passive review, as we touched on in Introduction, is that it leads us to confuse the feeling of "this looks familiar" with the ability to actually recall it. The fact that a sentence feels fluent the fifth time you read it doesn't mean you'll be able to recall it once you close the book.

Trying to recall the answer, then checking it

Active recall is the exact opposite approach: instead of reading the information again, you try to pull it out of your mind with no cues at all, then check whether you got it right.

In the research literature this is usually called the "testing effect": picture two groups studying the same material for the same amount of time, one reads the text over and over, the other tests itself (for example, by closing the text and trying to recall it). In the long run, the group that tests itself remembers the material far better, even though it feels harder and less "fluent" while studying. That feeling of difficulty is exactly the sign that learning is taking place.

Flashcards naturally push you to do this

When you look at a flashcard, the answer side is hidden. Before you see it, you have to try to find it in your mind: this is an active recall exercise built directly into the flashcard format itself. You don't need to make an extra effort, the format already pushes you in that direction.

Where the two ideas meet

Spaced repetition tells us when we need to review. Active recall tells us how we need to review. Each works on its own, but together they're far more powerful: you end up reviewing at the right time, in the right way.

We can now take a look at how a flashcard actually works in practice in Tsunagi, over in The Practice.