How does Smart Study optimize vocabulary reviews when time is limited?

Smart Study is a time-budgeted review tool in Tomaru that prioritizes your daily due queue. By estimating your reading speed, accounting for card difficulty, and ranking cards by memory gained per second, Smart Study selects your highest-value reviews to fit 5-, 10-, 15-, 30-, or 60-minute session limits.

What problem does Smart Study solve?

Spaced repetition algorithms answer one specific question: when should a card next appear for review? The mathematical output of a scheduler like FSRS-6 is a set of due cards.

Because algorithm design focuses on calculating decay intervals, a set of due cards has no native internal priority. On many days, the total number of due cards exceeds the time a learner has available. Schedulers do not decide which subset of cards to complete first, leaving learners to work down an unordered list until they run out of time or cut the session off arbitrarily. Both approaches risk missing the day's most critical memory updates.

Smart Study sits on top of FSRS-6 to answer the secondary question: when you have limited time, which cards should you review?

How do you choose a time budget?

Smart Study begins when you select a specific time allowance for your study session. You can choose one of five preset session lengths:

• 5 minutes
• 10 minutes
• 15 minutes
• 30 minutes
• 60 minutes

Once selected, Smart Study treats this duration as a strict boundary, assembling a custom queue designed to fit within your specified window.

How does Smart Study measure your answering speed?

A time budget requires an accurate measurement of your reading and recall speed. Tomaru calculates your pace directly from your study history, comparing total review time against cards completed.

To prevent over-promising how many cards you can finish, the pacing calculation deliberately leans slow. It evaluates your historical performance and applies a safety margin so your target schedule reflects a realistic, deliberate pace rather than an idealized sprint. Pessimistic pacing ensures that your study session finishes within your actual available time rather than overrunning your schedule.

How does Tomaru estimate the time cost of each card?

Cards carry different time costs depending on their state and your probability of recalling them. A new card requires time to read and absorb, while a card currently in active learning demands careful focus.

Review cards represent the most distinct contrast in time cost. A card you recall easily takes only a few seconds, while a card you fail requires reading, re-absorbing, and re-rating. Because Tomaru tracks your retrievability score for every card, it knows whether you are likely to recall a word before it appears. Cards you are about to fail are recognized as time-intensive before they enter the queue.

How does Tomaru rank review cards?

Tomaru ranks cards by how much memory durability they restore for every second of review time. When your study time is limited, the queue gives priority to the cards that offer the highest return on that investment.

How does Smart Study build your session?

Smart Study orders your daily session around cognitive momentum and retention value instead of serving cards in a fixed, alphabetical, or deck-by-deck sequence.

A session opens with words you are highly likely to recall, giving you a steady rhythm before you encounter difficult material. From there, the queue prioritizes items that return the greatest memory durability for the seconds required to review them. Cards you recently failed or are still acquiring stay active in the rotation to prevent lapses from fading, while severely overdue items are prioritized early so they do not fall out of memory entirely. New vocabulary enters the queue only after all due reviews fit comfortably within your allotted study budget. Throughout the entire session, Smart Study draws cards across all your active lists simultaneously rather than exhausting one list at a time.

Is Smart Study a reduced study mode?

No. Smart Study does not alter or bypass the FSRS-6 algorithm. Every card reviewed during a Smart Study session undergoes full FSRS-6 scheduling, updates its retrievability, stability, and difficulty scores, and writes to the same review record as standard reviews.

Smart Study only determines selection order and session boundaries. By prioritizing high-yield reviews, a focused 10-minute session targets the most vulnerable cards in your collection, preventing due queues from becoming overwhelming.

To learn more about baseline scheduling mechanics, read our guide on how spaced repetition works. To see how parameter optimization affects card intervals, read about personalized scheduling, or project long-term completion dates using the exam completion forecast.

Related questions

Why don't I see new cards during some Smart Study sessions?

Smart Study adds new cards only if your existing due backlog fits entirely within your selected time budget. If your due review queue consumes your available time, new cards are withheld to prevent accumulation of unmanageable review loads.

How does Smart Study know how fast I read cards?

Tomaru evaluates your historical review log to determine your average seconds-per-card, applying a conservative margin so your session plan accounts for difficult cards and slower study days.

Can I run Smart Study if I only have 5 minutes?

Yes. You can select a 5-minute session budget. Smart Study opens with high-probability cards to get you into rhythm quickly, then fills the remaining minutes with the reviews that return the greatest memory durability for the time spent.

Does completing cards in Smart Study update my FSRS parameters?

Yes. Reviews completed in Smart Study write to the same review record as standard reviews, contributing to your review history and future FSRS parameter optimizations.