[graboid]

Nice. I also have an implementation in Rust (no public repository, private note-taking app). One low-hanging fruit (IMO) to improve on the base SM-2 is to more smartly pick the initial ease. I just took the average ease of "similar" mature items. Since for my use-case, spaced repetition items are embedded in notes, "similar" items meant items in the same note, or in notes that were tagged similarly.

These days I often wonder if I should just switch to FSRS [1], which Anki also switched to. It delivers better results. However, I am hesitating, since I understand SM-2, and it is easy to read the code while FSRS is complex and feels kinda black-boxy, which wouldn't feel right to me.

A quick note to the implementation above: I wonder if having that many answer options is worth it. It probably increases the cognitive effort needed for grading and I wonder if the increased precision in some cases is worth that. But who knows?

[1] https://github.com/open-spaced-repetition

[adastra22]

Is there an actual problem that you'd be solving by switching algorithms?

[zetalyrae]

FSRS gives you the same retention for less work, or, equivalently, you can remember more things for the same amount of time worked.