The influence of non-technical factors on code review

When submitting a patch, the primary concerns of individual developers are “How can I maximize the chances of my patch being approved, and minimize the time it takes for this to happen?” In principle, code review is a transparent process that aims to assess qualities of the patch by their technical merits and in a timely manner; however, in practice the execution of this process can be affected by a variety of factors, some of which are external to the technical content of the patch itself. In this paper, we describe an empirical study of the code review process for WebKit, a large, open source project; we replicate the impact of previously studied factors - such as patch size, priority, and component and extend these studies by investigating organizational (the company) and personal dimensions (reviewer load and activity, patch writer experience) on code review response time and outcome. Our approach uses a reverse engineered model of the patch submission process and extracts key information from the issue tracking and code review systems. Our findings suggest that these nontechnical factors can significantly impact code review outcomes.