It was late in the school year, and I was giving my students an end-of-course assessment. We had worked hard all year, done some review leading up to assessment day, and both the students and I felt confident that we would be ready. So when I started grading the assessment, I was surprised to see that the topics that my students did worst on were some of the ones that we had learned most recently.

The benefits of spaced practice are more equivocal for tasks that require abstract thinking rather than only rote memory.