Comment by barrell

I would say the implementations are time optimized, over the others. I’m building a language learning application, and have put in a lot of effort to make sure that the Spaced Repeition is motivation-optimized.

It’s centered around your performance and review times, to make sure you aren’t struggling to much; no due dates to avoid Anki slogs; gamified with some internal mechanics; dopaminergically influenced with aspects of randomness.

Spaced Repetition is just an equation (SM2 is laughable simple), but a lot of applications just slap a UI on it and call it a day, but that’s not the only way to use it!