Announcing an experimental new tool for thought @michael_nielsen and I have been wondering: what happens if we take powerful ideas from cognitive science and deeply integrate them into explanations? Our first experiment in a new "mnemonic" medium: https://quantum.country/qcvc
It would certainly be very reasonable to expect that Khan Academy uses spaced repetition to assist retention—and indeed it once did in a limited sense as part of mastery challenges—but in fact, it doesn’t!
I used it before and remember it having spaced repetition. Was not aware it was only in a portion of the challenges. Many of my friends in medical school are huge fans of Anki decks, which allow them to focus their studying on concepts they haven't reviewed recently or done well.
I came to the thread and left with the impression that the author was the pioneer of incorporating these ideas into education, while knowing these 2 widely used examples which do utilize them, so I felt I should mention them. Certainly underutilized concepts though.