The core mechanism
Instead of studying a topic once and re-reading your notes before the exam, spaced repetition breaks review into short sessions spread out over increasing intervals—a day, then a few days, then a week, then longer—with the timing driven by whether you actually recalled the material correctly.
Correct, confident recall pushes the next review further away. Incorrect or shaky recall pulls it closer. Over time this concentrates your effort on the material that is actually at risk of being forgotten.
Why spaced beats massed review
Studying the same material repeatedly in one sitting—sometimes called massed practice or cramming—produces a strong short-term feeling of familiarity that does not hold up days later. Spacing sessions apart, even though it feels less thorough in the moment, tends to produce recall that lasts longer.
This is not an argument against ever cramming; a short cram session before a specific test can still help in the short term. It is an argument against treating cramming as a substitute for a spaced schedule over the course of a term.
What makes a scheduler adaptive
A basic spaced repetition system might use a fixed sequence of intervals for every card. An adaptive algorithm like FSRS instead builds a model of each individual memory's stability from your actual review history, so two cards you learned on the same day can end up on very different schedules depending on how reliably you recall each one.
This matters because not all material fades at the same rate—a definition you already knew loosely before a course started is not the same as a brand-new, unfamiliar term, even if you added them to your deck on the same day.
How Cueable applies it
Cueable uses FSRS-based spaced repetition as its scheduling engine, combined with deadline-aware planning so a fixed exam date can shift the mix of what gets reviewed sooner. The scheduling decides when; your practice mode decides how you retrieve it—typed recall, cloze, reconstruction or spoken explanation, among others.