Improving complex task performance using a sequence of simple practice tasks.

Online coding tools are an increasingly common feature of programming courses, providing students with rapid feedback and flexible practice opportunities and providing instructors with useful analytics. However, little research has explored the complexity of online exercises provided to students and the order in which students are exposed to new ideas. In this paper, we investigate the benefits of using a short sequence of practice exercises, each targeting a distinct topic, prior to having students solve a goal task that combines the concepts. As expected, we find students solve the goal task with fewer errors and in less time after completing the practice tasks. However, we also find that the practice tasks reduce the likelihood of students delaying work on the goal task, and these effects are particularly large for less-experienced students.