The testing effect
When you test yourself and successfully recall something, you remember it better later than if you'd spent the same time re-reading it. This is called the testing effect, and it's well established in cognitive science (Roediger and Karpicke's work is a landmark — see our sources page).
The key is that recognizing an answer ('oh yes, that looks right') is not the same as recalling it from scratch. Flashcards work because they force genuine recall: you see the prompt, answer in your head, then check.
Why re-reading fools you
Re-reading makes material feel familiar, and we mistake that familiarity for knowing. But familiarity disappears the moment the notes are gone. Retrieval practice trains the thing you actually need on a test or in real life: producing the answer without the page in front of you.
How to study with active recall
Turn what you're learning into questions and answer them from memory before checking. Cover your notes and try to reproduce the key points. Use flashcards and always answer before flipping. The harder you have to think to retrieve something (without giving up), the more the recall is worth.
Pair active recall with spaced repetition for the biggest effect: retrieve, space the next retrieval out, repeat. That combination is exactly what Koydo is built around.
