But output quality is only one of several benefits. And indeed, as software engineers we often claim the primary goal of code reviewing is to find defects. In fact, we also want reviewing to ensure our code's long-term maintainability; we treat it as a knowledge sharing tool, and an avenue to broadcast ongoing progress [1]. On the surface, these are different purposes, but the common thread is that code reviews allow a group of people to communicate over a shared view of an artefact undergoing a change.