Peer review is a
common quality control practice in both science and software
development. In this research, we investigate peer review in the
development of Linux by drawing on network theory and network analysis.
We frame an analytical model which integrates the sociological principle
of homophily (i.e., the relational tendency of individuals to establish
relationships with similar others) with prior research on peer-review
in general and open-source software in particular. We found a relatively
strong homophily tendency for maintainers to review other maintainers,
but a comparable tendency is surprisingly absent regarding developers’
organizational affiliation. Such results mirror the documented norms,
beliefs, values, processes, policies, and social hierarchies that
characterize the Linux kernel development. Our results underline the
power of generative mechanisms from network theory to explain the
evolution of peer review networks. Regarding practitioners’ concern over
the Linux commercialization trend, no relational bias in peer review
was found albeit the increasing involvement of firms.