Retrievability

Yuhimo uses FSRS-light to schedule learning pages.

• Stability estimates how long memory can last
• Difficulty estimates how hard the page is to retain
• Retrievability estimates how likely recall is right now
• Due date is the practical result shown to you

1. Learning page has scheduling state
2. Time passes and retrievability changes
3. The page becomes due
4. You review it in a session and grade recall
5. Scheduling state updates

You see simple review behavior. Yuhimo handles the internal estimate.

A high retrievability estimate means the page is still expected to be remembered. A lower estimate means the chance of forgetting is higher.

As more time passes after a review, retrievability usually decreases.

Pages with higher stability usually keep retrievability longer. Pages with lower stability usually become due sooner.

Yuhimo uses retrievability as one input when it schedules reviews.

What you see in the app is simpler: a page becomes due when its scheduled review date has arrived — today or in the past. You do not watch or edit a retrievability score.

The due date is not random. Two pages reviewed on the same day can still get different next dates because their history and scheduling state differ.

A page that was repeatedly marked Easy may stay above the review threshold longer. A page recently marked Hard or Again may become due sooner.

Retrievability is time-sensitive.

Right after a successful review, the page is usually considered easier to recall. After several days or weeks, recall becomes less certain.

This does not mean you failed. It is the normal reason spaced repetition exists.

A page reviewed today may not need another review tomorrow. But after enough time passes, Yuhimo may bring it back before the memory becomes too weak.

Confidence is subjective. Retrievability is an internal scheduling estimate.

You can feel confident but still miss details. You can feel unsure but recall correctly.

The review grade should be based on actual recall during the session. That is why Yuhimo uses self-assessment.

Each review grade sends a different signal:

• Again — recall failed or was not good enough
• Hard — successful but effortful recall
• Good — normal successful recall
• Easy — strong recall

After a review, Yuhimo updates the page's scheduling state. That update affects future retrievability and the next due date.

See How reviews work for the review flow.

Reviewing early means the page may still have high retrievability. Early successful reviews usually should not create as much scheduling progress as on-time reviews.

Reviewing late means retrievability may have dropped more than expected. A successful overdue review can indicate stronger retention than expected.

Yuhimo accounts for early or late timing in scheduling. See Early and late reviews for detail.

A page may not be due because:

• retrievability is still estimated to be high enough
• it was reviewed recently
• it has high stability
• the previous review grade pushed it farther out
• the current calendar day already has a grade

See Why isn't my page due? and One grade per day for more detail.

• Review pages when they are due
• Do not force early reviews unless there is a reason
• Grade based on actual recall
• Use Again when recall fails
• Use Hard when recall works but takes effort
• Use Good for normal recall
• Use Easy only for clearly strong recall
• Improve or split pages that repeatedly feel hard

FSRS-light explained — overview of the scheduling model.

Stability and difficulty — internal scheduling signals.

How reviews work — the review session flow.

Early and late reviews — how review timing affects scheduling.

One grade per day — why each page gets one rating per day.

Self-Assessment — why you choose the rating.

Can I see or edit retrievability?

No. In the normal Yuhimo workflow, retrievability is an internal scheduling estimate.

Does low retrievability mean I forgot the page?

No. It means Yuhimo estimates recall may be less reliable. The actual result is only known when you review the page.

Why is a page not due yet?

Because Yuhimo may still estimate that recall is strong enough, or because the page was reviewed recently, has higher stability, or is affected by review timing rules.

Can two pages have different retrievability after the same review grade?

Yes. Review history, stability, difficulty, and timing can make two pages behave differently even after the same grade.

Does Easy reset retrievability?

A successful review updates the scheduling state and usually increases future scheduling confidence, but the exact effect depends on the page state.

Should I try to optimize retrievability manually?

No. Grade honestly and improve page quality. Yuhimo handles the internal scheduling estimate.