Firstly, thank you Mike (and whoever’s working with you) for trying to deliver a nice experience to your users. I believe we all highly appreciate your taking the time to discuss improvements with the community.
Now, onto my small thoughts.
I am not convinced by the user experience regarding the “hard” button. If seems to me incompatible with the fact the sentence is 100% mastered. Intuitively, if I find a sentence to be hard, I don’t want to review it in over 180 days; I can be sure I’ll have forgotten by then. In my opinion, two buttons would be enough.
Additionaly - and that’s a separate thought, it seems to me that users are essentialy eager to have two things: 1) keep the review time more or less normal ; or 2) push the review way further in time when it feels like reviewing the sentence is a waste of time.
So, maybe pushing the “normal” button shouldn’t change the interval, and pushing the “easy” button should multiply it by whatever factor, possibly 2 by default?
You mentioned setting the multipliying factors for those two could appear in settings, and that’s one way to settle the decision. This would allow the configuration I just described, by choosing “1” for normal. Pressing enter would by default press “normal”, and people like @Ceid (whose post I think made several good points), could keep studying the way they want to.
As a sidenote - fairly unrelated, if you’ve completely played a collection, and you play it anyway, you’ll review words even though they’re not ‘ready’.
I’ve never used that myself, but I think I might when I feel like forcingly reviewing a collection at a random time, even though its review pile hasn’t stacked up.
I like the idea of the interval increasing, since it can really get out of proportions with the daily number of reviews. I personally find almost humoristical that the review times might be larger than a year - it seems to me unlikely that I’d even be using clozemaster on the same collections at that point, but based on the fact some people are really long-time, loyal users, it seems to be relevant.