Check It Off: Exploring the Impact of a Checklist Intervention on the Quality of Student-authored Unit Tests.

Software testing is an essential skill for computer science students. Prior work reports that students desire support in determining what code to test and which scenarios should be tested. In response to this, we present a lightweight testing checklist that contains both tutorial information and testing strategies to guide students in what and how to test. To assess the impact of the testing checklist, we conducted an experimental, controlled A/B study with 32 undergraduate and graduate students. The study task was writing a test suite for an existing program. Students were given either the testing checklist (the experimental group) or a tutorial on a standard coverage tool with which they were already familiar (the control group). By analyzing the combination of student-written tests and survey responses, we found students with the checklist performed as well as or better than the coverage tool group, suggesting a potential positive impact of the checklist (or at minimum, a non-negative impact). This is particularly noteworthy given the control condition of the coverage tool is the state of the practice. These findings suggest that the testing tool support does not need to be sophisticated to be effective.