Review Scheduling

How your reviews are actually scheduled, for anyone who wants the real mechanism, not just the marketing version.

MasteryLoop schedules reviews using SM-2 (SuperMemo-2), the same algorithm behind widely-used spaced-repetition tools like Anki — with one minor, disclosed exception (see the note at the end).

The quality scale

Every time a concept is tested — through a comprehension check or the final Teach-Back — it's scored 0 to 5:

Score	Meaning
5	Perfect, confident, complete recall of the reasoning
4	Correct, after a moment's hesitation
3	Correct, but recalled with real difficulty
2	Incorrect, but the right answer is easy to recognize once shown
1	Incorrect, though some of the right idea is there
0	Complete blackout — no real recall

A score of 3 or higher counts as a pass. Below 3 is treated as a miss.

Note: a question testing why something matters, not just what it is, is capped at a 2 if the answer only names the term without explaining the reasoning — recognition alone isn't full credit.

How timing is calculated

Every concept carries its own "ease factor" — a multiplier that starts at 2.5 and moves with your performance.

The first review comes one day after you finish the concept. The second comes a fixed six days later. From the third review onward, each interval is the previous interval multiplied by that concept's ease factor, rounded to the nearest day — so well-known concepts get reviewed less and less often. The multiplication uses the ease factor as it stood before the review being graded, so a score you just earned shapes the interval after next rather than the one you're given now.

Every score adjusts the ease factor by a fixed amount:

Score	Ease factor change
5	+0.10
4	No change
3	−0.14
2	−0.32
1	−0.54
0	−0.80

The ease factor never falls below 1.3, however many times a concept is missed.

A missed review — any score below 3 — also resets the interval ladder: the concept comes back in one day, then six days, then resumes multiplying. The ease factor itself is not reset. It keeps its reduced value, so every interval after a lapse stays shorter than it would have been without one.

Two details worth knowing

A review interval is measured in full 24-hour periods from the moment you answer — not from a calendar day, and not from when it was originally due. Answering late doesn't compress your next interval; there's no penalty beyond the delay itself.
The Teach-Back exercise can only flag a concept as weak (bringing it back sooner) — it never marks a concept as "confirmed strong." Not being flagged isn't treated as extra evidence you know it well.

A note on precision

MasteryLoop's implementation follows the standard SM-2 formula, with one documented exception — the very first time a concept is scheduled, timing doesn't yet account for prior history on that concept (which rarely matters in practice, since it's the first review anyway). We're noting this here so this document stays fully accurate, not just simplified for marketing.