Spaced repetition is more than memorization – it’s also generalization.
Just like when you reread a book or rewatch a movie that you haven’t seen in a while – you see things that you didn’t notice before. You come in with a different mental state, and you come out with some new perspectives.
For instance, a review by Smith & Scarf (2017) recounted multiple studies demonstrating that “spacing not only benefits the learning and retention of specific items but improves the generalization of learning.”
And while spaced repetition is often mischaracterized as “just memorizing flashcards,” it seems that when comparing spaced to massed practice, the greatest benefit occurs for complex generalizations!
So however much you think that spaced practice is improving your directly practiced skills as compared to massed practice… it’s improving your complex generalizations even more.
The idea behind interleaving is that, after you’ve learned a skill to the point that you can execute it accurately and consistently, you’ll maximize your learning if you start “mixing it up” with other skills.
