View Source Anki Algorithm for Review Cards

From Anki Algorithm Explained in 5 minutes!

ease-factors

Ease Factors

  • Default starting ease: 250%
  • Default interval modifier: 100%
  • Default hard interval: 120%
  • Default easy bonus: 130%

responses

Responses

  • Press <again>: Go through lapse steps, then new interval becomes % of old interval AND subtract 20% from ease
  • Press <hard>: new_interval = current_interval 1.2 (default hard interval) 1 (default interval modifier) AND subtract 15% from ease
  • Press <good>: new_interval = current_interval 2.5 (ease%) 1 (default interval modifier) AND keep ease unchanged
  • Press <easy>: new_interval = current_interval 2.5 (ease%) 1 (default interval modifier) * 1.3 (default easy bonus) AND add 15% to ease

The Anki algorithm as described herein only applies to graduated (review) cards, not cards in the learning phase.

anki-scheduler

Anki Scheduler

The Anki scheduler is in anki/pylib/anki/scheduler/v2.py.