The grey area in Figure1 reveals the inner workings of the review process from a white box perspective: Once source code is submitted for review, the reviewers decide whether they accept it (3) or not (4). Their decision is normally based on the project’s quality acceptance criteria, reviewing checklists, and guide lines. If they do not accept the code, reviewers annotate it with their suggestions (4) and send the reviewed source code back to the author. Addressing the reviewers’ suggestions, the author makes alterations to the code and sends it back for further review (5).