Reducing Code Navigation Effort with Differential Code Coverage

Programmers spend a significant amount of time navigating code. However, few details are known about how this time is spent. To investigate this time, we performed a study of professional programmers performing programming tasks. We found that these professionals frequently needed to follow execution paths in the code, but that they often made faulty assumptions about which code had executed, impeding their progress. Earlier work on software reconnaissance has addressed this problem, but has focused on whether the technique could provide the correct information to a programmer, not on whether the technique reduces or improves navigation. We built a tool, called Tripoli, that provides an approximation to software reconnaissance via differential code coverage and reran a subset of the initial study. We found that Tripoli had a positive effect on code navigation: less experienced programmers with Tripoli were often more successful in less time than experienced programmers without.