Guides
How the method works, written for people who want the mechanism rather than the motivation.
What is spaced repetition, and why does it work?
Spaced repetition schedules reviews at widening intervals, just before you would forget. Here is the mechanism, the evidence behind it, and how to run it without burning out.
8 min readRead
How the SM-2 algorithm works
SM-2 is the scheduling algorithm behind Anki and most spaced repetition apps. Here is exactly how ease factors and intervals are calculated, with the real constants.
7 min readRead
How many words do you need to speak a language?
Frequency data gives a clear answer: a few thousand words carries ordinary conversation. Here is what each vocabulary milestone unlocks, and how long it takes.
6 min readRead