Impact of Installation Counts on Perceived Quality: A Case Study on Debian

Software defects are generally used to indicate software quality. However, due to the nature of software, we are often only able to know about the defects found and reported, either following the testing process or after being deployed. In software research studies, it is assumed that a higher amount of defect reports represents a higher amount of defects in the software system. In this paper, we argue that widely deployed programs have more reported defects, regardless of their actual number of defects. To address this question, we perform a case study on the Debian GNU/Linux distribution, a well-known free / open source software collection. We compare the defects reported for all the software packages in Debian with their popularity. We find that the number of reported defects for a Debian package is limited by its popularity. This finding has implications on defect prediction studies, showing that they need to consider the impact of popularity on perceived quality, otherwise they might be risking bias.