How memory works
FSRS-6: How we learned to schedule remembering
Why do we forget words, and when should we review them? This nine-part series explores the science of memory, from Ebbinghaus’s experiments to FSRS-6, and shows how OOWN turns practice into a review schedule.
9 parts · 34 min total · OOWN team
Start from part 1 - 01
Why a familiar word can slip away
A word can look familiar and still fail to come when you need it. Recognition and recall ask different things of your memory.4 min read - 02
The man who tried to measure forgetting
Hermann Ebbinghaus studied forgetting by measuring the work needed to learn something again, even when he could no longer recall it.3 min read - 03
What a forgetting curve can and can't tell you
Forgetting doesn't follow one universal countdown. The curve describes a pattern, while a useful schedule needs more context.4 min read - 04
When is a review worth your time?
An immediate repeat and a review after a long break provide different evidence. A useful schedule balances practice, recall, and time.4 min read - 05
Why one review calendar doesn't fit everyone
A fixed review schedule can be a useful start. Different words and different learning histories soon call for different intervals.4 min read - 06
How review schedules learned to adapt
Card boxes, SM-2, and FSRS each carry information from an answer into the next review. What they remember about the card differs.4 min read - 07
The three estimates behind an FSRS review
Difficulty, stability, and retrievability help FSRS turn a review history into an estimate of when to ask again.4 min read - 08
What changed in FSRS-6
FSRS-6 expanded to 21 parameters, made forgetting-curve decay trainable, and revised how short review intervals affect stability.3 min read - 09
How OOWN turns practice into a review schedule
OOWN interprets exercise results before updating FSRS-6, so practice can inform the schedule without counting every repeat as fresh evidence.4 min read