One impression it’s had on me is strengthening a belief in interleaving content as a critical component of learning. The authors argue that much of what happens in learning is massed practice—the repetition of concepts to build strength—but that research shows that massed practice leads to an illusion of learning that quickly breaks down when the studied concept is meshed with other concepts. They argue that interleaving concepts is critical to develop skills of discrimination that lead to mastery. Interleaving feels less productive and it’s slower, but the end result is much stronger.
Another impression was the research on retrieval as a critical component of learning. The idea is that most students study by rereading content, or highlighting content, or looking over notes, but that the research shows that forcing yourself to retrieve content, either through quizzing or elaboration or summarizing, is the strongest way to learn material.
In any case, big thumbs up from me, and I’d be interested to discuss more with anyone else who has read the book.