Yes, I think he made a mistake.
https://chalkbeat.org/posts/us/2019/...work-research/
Personally I think the entire rote learning of facts and then testing the memorization of them system of education is horrible. Sure, it can be, ummmm, tested to see if it works. But it's also a great way to turn kids off of school and learning at an early age. There are much better ways to learn things.