I'm building a SRS language learning app [1] so I've thought about this topic a bit, but I've come to a conclusion that srs algorithms might be just a nerd optimization obsession. My app has "stupid" 1,3,7,15,30 or something like that intervals, and the reality is that if I know a card, I can swipe it within 2 seconds, and if I just barely know it, I can spend 30 seconds on it.
So optimizing the algorithm such that every card comes at the exact right moment might cause all cards to feel too hard or too easy. I think having a mix of difficult and easy cards is actually a feature, not a bug.
Don’t fool yourself into thinking a suboptimal SRS is going to be optimal at the motivational aspect. If a user needs a self-confidence boost during a flash card session, this should be a design choice, not due to poor performance of the core SRS algorithm.
Choose your SRS algorithm to best predict what a user knows and when they’re likely to forget it.
If your application decides that it wants to throw some softballs, that’s an application level decision. If you care about psychology and motivation, build a really good algorithm for that. Then blend SRS with motivation as desired.
Thank you for the report! I was thinking of redoing the landing page for a while anyway. Are you using a niche browser or something like that? I haven't had anyone experience this issue nor was I able to reproduce it.
So optimizing the algorithm such that every card comes at the exact right moment might cause all cards to feel too hard or too easy. I think having a mix of difficult and easy cards is actually a feature, not a bug.
[1] https://vocabuo.com