It's very surprising to me that elaborative explanation, summarizing, and self-explanation score lower than practice tests. I've found that trying to teach something to somebody else is the fastest way for me to determine if I really understand something.

So that method might be fast, but it isn't accurate, your explanations could easily be wrong without you knowing they are wrong. So even though you feel like you know it if you can explain it, many times people are wrong and give wrong explanations but still feel like they are experts, don't be one of those people.

It looks like the type of practice test matters a lot:

> a multiple-choice practice test increased intrusions of false alternatives on a final cued-recall test when no feedback was provided, whereas no such increase was observed when feedback was given

Sounds like practice tests are most useful when they are graded and the student gets that feedback. I suppose that makes sense. Flash cards and practice problems also fall under practice testing and it sounds like they were less effective.

It doesn't surprise me. Practice tests can show you you are unambiguously wrong about the details of things in a way writing my own summaries can't unless you go over them with a fine toothed comb anyway.