A set of exercises and tests for teaching tracing skills using a mastery approach

We present a first implementation of exercises on code evaluation and tracing for use alongside introductory programming courses. The goal of these exercises and accompanying tests is to provide a structure that enables students to fully master a number of common tracing skills. In developing the exercises, we focused on keeping cognitive load as low as possible by gradually introducing new programming language elements, while allowing for repeated practice of previously introduced concepts. The exercises range from evaluating expressions involving integer division to tracing loops with multiple variables. We also generated small tests that students take to show their mastery of the concepts, allowing only a very limited number of mistakes per test and requiring students to take another version if needed. Using this model in several introductory programming courses over the past year shows that it appears to be possible to achieve mastery on these tracing skills for almost all students while maintaining positive attitudes toward the exhaustive training process.