I did want to give some feedback, though. I think this post suffers from too much hand-waving, which is what plagues most other posts about learning and spaced repetition (excluding probably just Gwern). For example, it compares flash cards and reading to just reading, citing the results of the study as a negative:
> This is however a very slow process. One study implies that in the best case it takes adults 10 years of reading 1 hour a day to get twice as effective at reading. Even if this is technically learning exponentially, the improvement rate is so slow that the process is indistinguishable from a linear one.
...
> We said in the best case it takes adults 10 years to get twice as effective reading. With spaced repetition it takes only days for your time to get twice as effective. These growth rates are completely different.
Maybe the rate of change of effectiveness of the reading is slow, but does that matter if you're accumulating knowledge from all of that reading, especially as it builds off of prior knowledge? I also don't think it's a 1:1 comparison to contrast these. It only takes days to get twice as effective at reading with spaced repetition? Or at learning? If it's the latter, I don't think that's what the earlier study measured?
The other thing that jumped out at me is the huge focus on spaced repetition and memory for learning, which are absolutely helpful, but there seems to be a lack of what constitutes memorizing versus understanding (and I'm not sure I see that in the Learning is Remembering post either). I think about other ways to build your understanding, like working through problems and applying the knowledge, that are key to learning. Much of learning physics is getting your hands dirty in the equations, and there's a big difference between knowing a formula and really understanding it in action.