Wait For It: Determinants of Pull Request Evaluation Latency on GitHub

The pull-based development model, enabled by git
and popularised by collaborative coding platforms like BitBucket,
Gitorius, and GitHub, is widely used in distributed software
teams. While this model lowers the barrier to entry for potential
contributors (since anyone can submit pull requests to any repository),
it also increases the burden on integrators (i.e., members
of a project’s core team, responsible for evaluating the proposed
changes and integrating them into the main development line),
who struggle to keep up with the volume of incoming pull
requests. In this paper we report on a quantitative study that tries
to resolve which factors affect pull request evaluation latency
in GitHub. Using regression modeling on data extracted from
a sample of GitHub projects using the Travis-CI continuous
integration service, we find that latency is a complex issue,
requiring many independent variables to explain adequately.