How Ember decides when you see a word again
Four honest buttons and a scheduler called FSRS. Here is what happens after you press one.
After you flip a card, Ember asks one question: how did that go? You answer with one of four buttons — Forgot, Hard, Good or Easy — and each one tells you what it will do before you press it.
The scheduler
Behind the buttons is FSRS, a modern spaced-repetition algorithm. For every card it keeps an estimate of how stable the memory is and how difficult the word is for you. From those it predicts the moment you are about to forget — and schedules the next review just before it.
Why honesty pays
The only way to game a spaced-repetition system is against yourself. Pressing Good on a word you half-remembered pushes it further away than it should go, and it comes back as a stranger. Pressing Hard costs you one extra review and saves you relearning it later.
What you will notice
- New words come back quickly, then less and less often.
- Words you struggle with stay close until they settle.
- Your daily goal stays small enough to finish.
The deck is the product; reading is how the deck grows. The scheduler just makes sure you do not lose what you have already earned.