  Given the increasing number of unsuccessful pull requests in GitHub projects,
insights into the success and failure of these requests are essential for the
developers. In this paper, we provide a comparative study between successful
and unsuccessful pull requests made to 78 GitHub base projects by 20,142
developers from 103,192 forked projects. In the study, we analyze pull request
discussion texts, project specific information (e.g., domain, maturity), and
developer specific information (e.g., experience) in order to report useful
insights, and use them to contrast between successful and unsuccessful pull
requests. We believe our study will help developers overcome the issues with
pull requests in GitHub, and project administrators with informed decision
making.
