Spaced repetition memory systems are extremely efficient. In fact, they’re so efficient that once someone’s adopted a reliable spaced repetition habit, system “throughput” tends to be limited by how many good prompts they can write, rather than by how much material they can absorb.
Writing good spaced repetition memory prompts is hard. The obvious solution is to pool prompts like Quizlet and others do, but Studying another person’s spaced repetition memory prompts is usually ineffective. The Mnemonic medium is one solution: The mnemonic medium may help scaffold prompt-writing through author-provided prompts.
For instance, I find that I can handle about 40 new prompts per day while still keeping my sessions a reasonable length. And if I spend an hour or two reading per day, I’ve probably consumed enough material to warrant 40 prompts. But writing 40 prompts will add 30-60 minutes of effortful work to otherwise casual reading sessions, so I may write only a handful. That might be better in some ways: maybe I shouldn’t continue to engage with material I don’t care enough about to write prompts about. But my instinct is that we’re not at the efficient frontier. There is material for which I wouldn’t write prompts myself, but for which I’d benefit from reviewing prompts. And the process could be made less effortful for the material I would prompts about (modulo Writing one’s own spaced repetition prompts seems to promote understanding).
In sum, solving this problem might be the practical difference between remembering everything interesting that I read, and remembering 10% of the most interesting things I read. If I really did add 40 prompts to my collection every day, that would be almost 15k items in a year! See What’s the maximum intake rate of an efficient spaced repetition memory system?
Tentatively, I’ve found that writing prompts in the context of my own notes is less effortful; the typical number I write on a topic is higher in that context than when studying with a memory system alone. (See The mnemonic medium can be extended to one’s personal notes)