A century of memory research agrees on one thing: six one-hour sessions spread over two weeks beat one six-hour cram, every time, for retention that survives past the exam. Here's the exact schedule — spacing, session lengths, and hours by grade weight.
Every time you retrieve something as it's starting to fade, the memory comes back stronger and fades slower — the spacing effect, first measured by Ebbinghaus in 1885 and replicated relentlessly since. Cramming stores everything in the steepest part of the forgetting curve: enough to feel familiar the next morning, gone by the final.
Work backwards from exam day with sessions at expanding intervals — closer together near the exam, when review is most valuable:
| Session | When | Focus |
|---|---|---|
| 1 | ~16 days out | First pass — map what the exam covers, flag the hard parts |
| 2 | ~11 days out | Active recall on pass one (practice problems, blank-page recall) |
| 3 | ~7 days out | Weak spots from session 2, second pass on the rest |
| 4 | ~4 days out | Full mixed practice under time pressure |
| 5 | ~2 days out | Heaviest session — full review, hardest material first |
| 6 | 1 day out | Light final pass. Then sleep — consolidation is study |
Weight the minutes toward the end: if session 1 is an hour, session 5 might be 90–120 minutes. If the exam is closer than 16 days, drop the earliest sessions and keep the near ones.
These aren't magic numbers — they're a sane default you adjust with experience. The principle that matters: points earned per hour studied collapses when all the hours land the night before.
One exam = six sessions. A normal course load = 15–20 exams and quizzes a semester = 80+ sessions to schedule around classes, work, and life — and to re-schedule every time something slips. This is precisely what Kairos automates: import a syllabus and every exam becomes a weighted spaced-prep schedule, placed around your real life, self-repairing when you miss a session.
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