Request for comments: conversation patterns in issue tracking systems of open-source projects

Issue tracking systems play an important role in developing software systems. They provide a central place to store and maintain different development artifacts. Various studies are concerned with the contained bug reports, features, the relations among them and traces to the projects code base. However, an issue tracker can also be used as a communication channel between project contributors by attaching comments to issues. Less is known on how users actually utilize this functionality. In this paper, we study more than 270,000 comments from twelve open-source projects. We analyze to what extend comments are used and then study the structure occurring in threads of comments. Based on the order of comments and participating contributors, we identified three patterns of conversation: monolog, feedback, and collaboration. Our results show that most conversations are collaborations among two or more developers discussing the issue.