What spaced repetition is
Spaced repetition means reviewing material in several short sessions spread out over days and weeks instead of putting every exposure into one sitting. A large review by Cepeda and colleagues synthesized 839 assessments from 317 experiments on verbal recall. On average, distributed practice improved delayed retention relative to massed practice. The review also found that the most useful spacing depends on how long the learner needs to remember the material, so there is no single perfect interval for every student or topic.
The forgetting curve
In the 1880s, Hermann Ebbinghaus ran some of the first controlled experiments on memory by testing his own recall after different delays. His results helped popularize the idea that newly learned material can be forgotten quickly and then more gradually. Modern research shows that the shape and speed of forgetting vary with the material, the learner, and the way recall is tested. The figure below is a useful schematic, not a prediction of any student's exact memory.
Why cramming is weak for delayed recall
Cramming can improve very near-term familiarity, which is why it often feels effective. It provides fewer chances to retrieve the same idea after a delay, however. If the goal is to retain vocabulary or a method until a later test date, several separated reviews are generally a better fit with the evidence than one uninterrupted block.
Spacing can also make a later retrieval attempt more effortful than an immediate repeat. Under suitable conditions, that effort can support learning. Difficulty is not automatically desirable, though. If the gap is so long that you cannot retrieve the idea, use a hint or review the explanation and shorten the next gap.
How to schedule reviews for SAT vocab and skills
You do not need a perfect algorithm to begin. Try a short review after an initial delay, then lengthen the next gap when you can recall the idea accurately. If you miss it, review the correction and return sooner. Treat those intervals as a starting point. The useful gap changes with the material, your prior knowledge, and the time remaining before the test.
For vocabulary, that means flashcard rounds where the words you know well show up rarely and the words you keep forgetting show up often. For skills, like comma rules or systems of equations, it means returning to a topic for a short set of practice questions days after you first drilled it, rather than considering it done. And make every review a self-test, not a re-read. Spacing schedules the work; active recall is what makes each review count.
How PsychSAT automates it
PsychSAT's vocabulary trainer combines recall practice with server-side review scheduling. Its default Recall workflow asks you to predict a word's meaning, choose the closest meaning, and read the feedback before moving on. Study mode offers the optional flip-card workflow. A first Easy rating schedules the word three days later, Hard starts at two days, and Forgot returns the next day. Later intervals adjust from the prior schedule and correct-answer history.
The study plan also considers mastery and spaced-review timing when it chooses future, unstarted work. After a completed study-plan session, PsychSAT can recompute mastery and retune future work while preserving started, completed, and pinned sessions. The schedule is a planning aid, not a guarantee that a skill will stay remembered without continued practice.
Start earlier than feels necessary
Spaced repetition needs enough calendar time for more than one delayed review. Starting earlier gives you more chances to retrieve, correct, and revisit the material than a final study weekend can provide. It pairs naturally with other useful prep, including the official practice described in our Bluebook practice test guide and the calm that preparation builds, covered in our test anxiety guide.