The practice that felt worse

Two groups of students practised the same material for the same length of time. One group studied each topic in a block: all of topic A, then all of topic B, then all of topic C. The other group mixed them, moving between topics throughout.

During practice, the blocked group performed better and reported feeling more confident. They were right about their performance at the time. On a test a week later, the mixed group scored substantially higher, and the gap was not small.

The explanation is about what each kind of practice rehearses. In a block, you know which method applies before you read the question, because you have just used it twenty times. The hard part of a real test is not executing a method; it is deciding which method the question calls for. Blocked practice skips that step entirely. Mixed practice forces it every time, which is why it feels harder and why it transfers.

The uncomfortable part is the confidence. Students, and teachers watching them, use performance during practice as a signal of learning, and here that signal points the wrong way. The method that feels most effective is the less effective one, and no amount of experience corrects the feeling.

The practical version is simple enough to try this week. When revising three topics, do five questions of each in rotation rather than fifteen of one. Expect it to feel worse. That feeling is the mechanism working.