Software Process Data Quality and Characteristics - A Historical View on Open and Closed Source Projects

Software process data gathered from bug tracking databases and version control system log files are a very valuable source to analyze the evolution and history of a project or predict its future. These data are used for instance to predict defects, gather insight into a project's life-cycle, and additional tasks. In this paper we survey five open source projects and one closed source project in order to provide a deeper insight into the quality and characteristics of these often-used process data. Specifically, we first define quality and characteristics measures, which allow us to compare the quality and characteristics of the data gathered for different projects. We then compute the measures and discuss the issues arising from these observation. We show that there are vast differences between the projects, particularly with respect to the quality in the link rate between bugs and commits.