How Cotobara's SRS Builds Your Review Schedule

Most spaced-repetition apps ask you to trust a black box. This post won't hand you a spreadsheet of intervals (those are ours to keep tuning, and a schedule you can game is a schedule that stops working), but it will tell you every rule that decides what you see and when.

If you want the general theory first, read spaced repetition for Japanese. This is what Cotobara actually does with it.

The ladder

Every word you learn climbs a ladder. The rungs are grouped into five stages you'll see named all over the app: New, Learning, Familiar, Known, Mastered. Each rung sets how long the word waits before it comes back.

A word you learn this morning is back in your queue the same day, again this evening, then tomorrow, then the day after. That tight early spacing is what stops a brand-new word from evaporating. From there the gaps stretch out fast, and a word you keep getting right soon costs you a handful of seconds a few times a year.

Two deliberate details:

• The early rungs are just under round numbers. If a word came back exactly a day later it would drift an hour later every cycle, and studying at 9am on Monday would mean studying at midnight by the weekend. Slightly-under-a-day keeps reviews landing at the time you actually study.
• No single jump is large. Every gap between one rung and the next is small enough that a word which was solid yesterday is still plausibly solid at the next asking. A ladder with a big jump in it is a ladder where a specific rung quietly becomes the place words go to be forgotten.

Two cards per word

Here is where Cotobara differs from most SRS setups. Every due word produces two cards:

• Recognition: the Japanese word is shown; you give the English meaning.
• Production: the English meaning is shown; you type the Japanese reading in kana.

The two are deliberately separated in the queue by a few other cards, so answering one doesn't hand you the other.

Production is always typed, at every stage. That's the card that proves recall, and a reading grades unambiguously where an English meaning does not. Recognition is typed too, except in the first day or two of a word's life, where it's answered by tapping one of four meanings. Lessons teach by tapping; reviews ask you to type. A brand-new word gets one rung of scaffolding between those two so your first typed card isn't also your first review.

And here is the rule that matters most: a word is graded once, on both cards combined. Get both sides right on the first try and the word promotes. Recognizing a word without being able to produce it is exactly the gap that shows up in an exam or a conversation, so Cotobara refuses to score it as a win.

What happens when you get one wrong

Missing a word costs you more the higher it had climbed, and more when you missed both sides than one:

• Miss one side and the word slips one rung. You knew the word; one direction wasn't there yet.
• Miss both sides and it drops two. That's not a slip, that's a word you've lost.
• In the New stages the fall is gentle in absolute terms anyway, because those rungs sit close together. Forgetting a word you first saw yesterday is normal; that's what those stages are for.

Within the session itself, a missed card doesn't go to the very back of the queue and it doesn't vanish. It comes back a few cards later, long enough that you're recalling rather than reading off your screen, soon enough that you get a second honest attempt in the same sitting.

Answering late still counts

Life happens; a review sits for a week. If you then answer it correctly, that's evidence the memory is stronger than the schedule assumed: it survived a gap longer than the one it was given. Cotobara credits some of that lateness toward your next interval rather than throwing it away.

That bonus only applies past the New stages, where being late means something. In the first day, when reviews are hours apart, everybody who sleeps is technically overdue.

Mastered isn't a graveyard

Plenty of SRS apps retire a word permanently once it reaches the top. Cotobara doesn't, for one reason: a word the app has stopped asking about is a word it can't honestly count toward your exam readiness.

So a mastered word comes back for a single re-check after a long gap, long enough that mastered words never become recurring queue noise, long enough that passing one genuinely means something. Pass and it stays mastered. Miss it and it drops back down the ladder like any other word.

What doesn't get taken away is credit you've already earned. Your mastered count and your Conquered level badges are cumulative: a word you once mastered is counted forever, even if a re-check knocks it back down and you have to climb it again.

Grading is strict about the answer, forgiving about the typing

Cotobara accepts every legitimate meaning a word has: its primary gloss, its alternate meanings, and any custom answers you've added yourself. It also forgives small spelling slips on longer answers, so a stray letter in "convenience" doesn't cost you a word you clearly knew.

What it does not do is quietly pass a wrong answer. And a few checks stop you from scoring yourself unfairly:

• Type a reading into a meaning card and the field shakes instead of grading: you knew the word, you just answered the wrong question.
• Leave stray romaji in a reading answer and it shakes rather than marking you wrong.

On reading cards you type romaji and it converts to kana as you go, so no Japanese IME is required, including on a phone. Hiragana and katakana forms are treated as equivalent, so you're never marked wrong for the script you chose.

Premium reviews without a daily limit

Cotobara's main throttle is how many new words you take on per day, up to 100 on Premium. Reviews are unlimited on Premium; the free plan takes on no new words and clears up to 50 a day, which keeps a deck you have already built in good order.

That cap is the throttle that keeps the system honest: every new word you learn today becomes roughly a dozen reviews spread over the next year. Picking a sustainable daily number is the single highest-leverage setting in the app.

Practicing without touching your schedule

Two places let you answer review cards with nothing written back:

• Your first lesson hands its words straight to a practice run through the real review cards, from the dashboard, so the review screen isn't something you meet alone hours later with your schedule riding on it. It's graded on screen and posted nowhere.
• Recent-mistakes practice is a quick flip-card loop over your latest misses that never submits, never promotes, never demotes. It's a warm-up, not a review.

Both are deliberately walled off from your SRS, so a practice round can't distort the schedule that's doing the real work.

Why this shape

The intervals aren't arbitrary. Each one sits near the point where you're about to forget: the moment when a successful recall does the most to strengthen the memory. Reviewing sooner is wasted effort; reviewing later means relearning from scratch. The ladder has enough rungs to run from a few hours to the better part of a year without any gap so large that words fall through it.

The rest is just showing up. The schedule handles what to study and when; you only have to answer honestly.

Start for free and learn your first five words. Your first review is waiting on the dashboard the moment you finish.