Spacing: Testing on a Schedule

Left alone, most of what you learn today is gone within a day or two — that's the forgetting curve, and it's normal brain behaviour, not a personal failing. But every time you retrieve the material before it fades completely, the curve gets flatter: you forget more slowly, and the memory lasts longer each time. This is the single most important scheduling fact in studying. Six twenty-minute sessions spread over two weeks beat one two-hour session, even though the total time is identical. The minutes aren't what matters — where they sit on the calendar is.

Here's the schedule: review the same day you learn it (ten minutes), then one day later, then three days later, then a week later, then two to four weeks later. The gaps expand because each successful recall buys you more time before the next one is needed. Notice the total: about an hour of reviewing, spread across a month, for material that then lasts months rather than days. And these reviews are tests, not re-readings — you close the book, retrieve, then check. A ten-minute review where you re-read your notes is not a review; it's the fluency illusion wearing a schedule.

Not everything deserves the same amount of review, so sort your questions or flashcards into three piles. STRUGGLING — you got it wrong or guessed: review daily. GETTING THERE — right, but slow or shaky: every two or three days. SOLID — fast, confident, complete: weekly, then monthly. A question moves piles based on today's answer, not last week's, so a 'solid' one you suddenly get wrong goes straight back to struggling. The reason this system matters: most students review what they already know, because it feels good. The pile system forces your minutes onto the material that's actually costing you marks.

Blocked practice means doing twenty questions of the same type in a row. It feels smooth — but you knew the method before you read the question, so you never practised choosing it. Interleaving means shuffling topics: a bit of A, then C, then B. It feels harder and your practice scores drop, and that's exactly the point, because every question now forces you to decide which method applies. That decision is the skill the exam actually tests. The sensible rule: learn a brand-new method blocked, until you can execute it. Then move it into the interleaved mix.

Here's what a real week looks like. Monday: new topic plus a ten-minute same-day review. Tuesday: yesterday's topic for the one-day review, plus a pass at the struggling pile. Wednesday: new topic plus same-day review. Thursday: Monday's topic again at three days, plus the struggling pile. Friday: an interleaved mix drawn from the whole week. Saturday: the weekly review of everything from seven days back. Sunday: rest, or one short struggling-pile pass. That's fifteen to twenty-five minutes of review a day on top of your normal work. And the most important rule: if you miss a day, do that review late. A late review still beats a skipped one — the schedule is a guide, not a contract you can break.