Yeah I initially went with the 80/20 rule. If I was getting more than 80% right, go faster and/or study less. Now I’m happier with something in the 90s because it keeps the re-review workload down more.
I usually get 96%-100%, but that’s because I tend to take my time with lessons, and I review items I failed, which keeps me pretty consistent.
Plus, you can’t really choose the difficulty of wk, since all level items are locked in. I guess you could increase your number of reviews to make it harder, but at that point you’re just challenging your endurance LOL
Perhaps I’m interpreting this wrong, but in the abstract it’s mentioned that the optimal succes rate is determined in the context of a binary classification task. That does not seem particularly applicable to learning Japanese (be it kanji, grammar, or other relevant skills).
Note: I did not read the entire paper, nor watched the video, so I might be completely off base here.