On what basis to recommend: Changesets or interactions?

Different flavours of recommendation systems have been proposed to help software developers perform software evolution tasks. A number of these recommendation systems are based on changesets. When changeset information is used, recommendations are based on only the end result of the activity undertaken to complete a task. In this paper, we report on an investigation that compared how recommendations based on changesets compare to recommendations based on interactions collected as a programmer performed the task that resulted in a changeset. To provide a common basis for the comparison, our investigation considered how bug reports considered similar based on changeset information compare to bug reports considered similar based on interaction information. We found that there is no direct relationship between the bug reports found similar with the different methods, suggesting that each comparison methods captures a different aspect of the problem.