How scheduling works
Vocapi uses FSRS, the Free Spaced Repetition Scheduler, to work out when each card should return. The schedule changes as you review.
Your answers and the time between reviews help Vocapi estimate how well you remember it.
What does the scheduler use?
Link to “What does the scheduler use?”FSRS keeps an estimate of a card’s difficulty and memory strength. It updates those estimates from your review history and uses the time since your last review to estimate the chance that you’ll remember the card now.
This is why two cards from the same lesson can have different due dates. You may remember one reliably while missing the other, and you may review them at different times.
What happens after an answer?
Link to “What happens after an answer?”One correct answer moves a new card into regular reviews. If you miss an answer, the card enters a short learning or relearning step. Each incorrect answer schedules that step for 10 minutes later if you leave it unfinished.
A correct answer, including a correction after a miss, ends that step. FSRS calculates the next interval from the updated memory estimate. That interval starts at the time of the correct answer.
As you remember a card across later reviews, the intervals grow. There isn’t one fixed timetable that every card follows.
Why does a missed card return in the same session?
Link to “Why does a missed card return in the same session?”Vocapi records the missed answer and brings the card back after you’ve tried every card in the session. Miss it again and it goes to the back of the retry queue. If it’s the only card left, it can return straight away.
Answering correctly clears the card from the session. Once you’ve cleared all the remaining cards, the session ends. Your accuracy reflects your first answers, so a completed session can still have a low score.
Every retry answer updates the card’s schedule. The original miss stays in your review history and accuracy score. Retrying doesn’t earn extra XP or add another activity or streak credit.
After you clear a card, it waits until its next scheduled review. Other cards can still become due while you study.
What does the 90% retention target mean?
Link to “What does the 90% retention target mean?”Vocapi’s scheduler uses a 90% retention target. That means it calculates an interval at which the model estimates a 90% chance of remembering the card.
The target guides the schedule. It isn’t a test score, and it doesn’t guarantee that you’ll get nine out of every ten answers right. Your actual answers update the estimate at each scheduled review.
Why aren’t the intervals exactly predictable?
Link to “Why aren’t the intervals exactly predictable?”Each card’s history affects its next interval. Vocapi also applies a small random variation to longer intervals, so the due date can differ slightly from the model’s initial calculation.
If you review a card late, the scheduler uses the time you actually reviewed it. It accounts for the time since the previous review when calculating what comes next.
For offline reviews, that is the time you studied the card, even if your answers reach the server later. Finishing offline saves your answers on the device, pending sync. Changes from another device can cause a sync conflict.
The next interval starts at the successful study time. If it has already passed by the time your answers sync, the card can be due again.
Where can I see my card’s history?
Link to “Where can I see my card’s history?”Open Why this card? during a scheduled review. It summarizes the available review-history details, including estimated memory strength and when you last reviewed the card.
To change whether a card appears in reviews, see Managing your cards.
Review basicsHow reviews workFor the technical model and formulas, see the FSRS algorithm reference.