How Knowledge Overlap Drives (and Doesn’t Drive) Developer Preferences for Joining Related Open Source Software Projects

Open Source Software communities are exemplars of online and virtual collaboration among software developers. However, such communities are typified by a scarcity of volunteers with the result that OSS projects typically strive to garner necessary expertise. This study attempts to understand how OSS projects can attract software developers to join its collective effort. We proceed by examining the role of a key construct, knowledge domain overlap, defined as the overlap between the expertise domain of a software project a developer is considering joining, and the combined expertise domains of her past software projects. While greater knowledge domain overlap should intuitively attract a developer to an OSS project this is not always so. Instead, we find that two contingencies -- community experience of a developer and the centrality of the OSS project in the community – play a counter-intuitive role in driving developer preferences for OSS projects. Our empirical analysis is based on the archival data of the joining behavior of 462 developers in 538 OSS projects. First, we find that developers prefer those projects more which have a higher knowledge domain overlap in both dimensions – technical and application domains. However, despite lower technical domain overlap projects are still able to attract developers who have greater community experience. Similarly, those projects which are centrally located in the community structure are also able to attract developers despite a lower technical domain overlap. In comparison, application domain overlap seems important across contexts. The findings have implications for knowledge-based innovation in open communities which are a hotbed of innovation