Documentation

Spaced Repetition

The SM-2 algorithm that schedules your reviews.

Why Spaced Repetition?

Your brain forgets on a predictable curve. Spaced repetition schedules reviews just before you forget — maximizing retention with minimum effort.

The SM-2 Algorithm

Each concept has three key values:

  • Ease Factor — How easy this concept is (starts at 2.5)
  • Interval — Days until next review
  • Review Count — How many times reviewed

Interval Progression

With consistent good scores (4/5):

Review #Interval
11 day
26 days
3~2 weeks
4~5 weeks
5+~3 months (max 180 days)

Pass vs Fail

On Pass (score ≥ 3)

  • Interval increases
  • Ease factor adjusts
  • Review count +1

On Fail (score < 3)

  • Interval resets to 1 day
  • Ease factor decreases
  • Review count resets

Mastery Criteria

A concept is "mastered" when:

  • Ease factor ≥ 2.5
  • Review count ≥ 3