The critical thing to optimize in spaced repetition memory systems is emotional connection to the review session and its contents. One possible lever here is to give users a low-friction way to de-prioritize material they don’t care about. In particular, perhaps we could offer a “skip” button which defers a prompt with exponential backoff. This would be a lower-stakes alternative to deletion: Spaced repetition can lower the stakes around destructive inbox-maintenance operations.
But would this be self-defeating? Would students over-use the button to the extent that no learning would happen?
68% of the items were dropped after only one correct response, and an additional 8% were dropped without having been answered correctly at all.
… Being able to drop items had especially negative effects for the 20% of participants whose study strategy was to drop items they judged difficult to learn
… In the interests of creating durable learning, items, if dropped, should be returned to later. Restudying previously dropped items provides additional spaced-learning opportunities on those items. It also identifies items that have not actually been learned and are in need of further study.
Whitmer (2020) ran an experiment on in-training Marines, giving one group the opportunity to drop cards. Those trainees had substantially worse memory in post-tests.
Kornell, N., & Bjork, R. A. (2008). Optimising self-regulated study: The benefits—And costs—Of dropping flashcards. Memory, 16(2), 125–136.
Whitmer, D. E., Johnson, C. I., Marraffino, M. D., Pharmer, R. L., & Blalock, L. D. (2020). A Mastery Approach to Flashcard-Based Adaptive Training. In Adaptive Instructional Systems (pp. 555–568). Springer International Publishing.