Degree-of-Knowledge: Investigating an Indicator for Source Code Authority

Working on the source code as part of a large team productively requires a delicate balance. Optimally, a developer might like to thoroughly assess each change to the source code entering their development environment lest the change introduce a fault. In reality, a developer is faced with thousands of changes to source code elements entering their environment each day, forcing the developer to make choices about how often and to what depth to assess changes. In this paper, we investigate an approach to help a developer make these choices by providing an indicator of the authority with which a change has been made. We refer to our indicator of source code authority as a degree-of-knowledge (DOK), a real value that can be computed automatically for each source code element and each developer. The computation of DOK is based on authorship data from the source revision history of the project and on interaction data collected as a developer works. We present data collected from eight professional software developers to demonstrate the rate of information flow faced by developers. We also report on two experiments we conducted involving nine professional software developers to set the weightings of authorship and interaction for the DOK computation. To show the potential usefulness of the indicator, we report on three case studies. These studies considered the use of the indicator to help find experts, to help with onboarding and to help with assessing information in changesets.