CAREER: SHF: Debugging Mental Models

George Mason University, Fairfax VA

Investigators

Abstract

When software fails to behave as intended, a software developer working to address this issue engages in the activity of debugging. Debugging is often challenging, as developers must generate possible hypotheses about a failure's cause, laboriously test hypotheses by reasoning about the behavior of complex code, and use debugging tools to generate and identify relevant runtime state. These challenges may be manifest to software users as software with unfixed defects and increased software cost. In addition, expert developers have knowledge which, if extracted, would be valuable in helping to debug more easily. Experts have long been shown to do even simple programming tasks over ten times more quickly than non-experts, largely because they have seen similar situations before. This project addresses the question of the nature of mental models of debugging and the creation of a scientific foundation for understanding, externalizing, and sharing expert insight into the runtime behavior of programs. This project encompasses a comprehensive set of activities for conducting studies of software developers and designing new forms of debugging tools. A broad sample of developers will be observed to collect sketches capturing mental models from debugging tasks, abstract common building blocks, and count the frequency of these building blocks. New types of debugging tools will be designed which enable developers to externalize their mental models by recording, abstracting, and replaying queries over program executions and visualizing relationships between elements within program executions. New debugging tools will be evaluated through user studies to understand if and how developers may externalize and share their debugging mental models. Together, these activities will deepen the scientific understanding of how developers debug and create new techniques for developers to work more effectively. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.