Node mixing and group structure of complex software networks

TL;DR

This paper explores the complex network structure of large software projects, revealing unique node mixing patterns and group structures that differ from other networks, with implications for software engineering.

Contribution

It uncovers the dichotomous degree mixing and various group structures in software networks, linking them to software project properties and advancing understanding of their topology.

Findings

Software networks exhibit dichotomous node degree mixing similar to biological networks.

Distinct clustering profiles and mixing patterns are identified in software networks.

Groups within software networks correspond to software project properties.

Abstract

Large software projects are among most sophisticated human-made systems consisting of a network of interdependent parts. Past studies of software systems from the perspective of complex networks have already led to notable discoveries with different applications. Nevertheless, our comprehension of the structure of software networks remains to be only partial. We here investigate correlations or mixing between linked nodes and show that software networks reveal dichotomous node degree mixing similar to that recently observed in biological networks. We further show that software networks also reveal characteristic clustering profiles and mixing. Hence, node mixing in software networks significantly differs from that in, e.g., the Internet or social networks. We explain the observed mixing through the presence of groups of nodes with common linking pattern. More precisely, besides densely linked groups known as communities, software networks also consist of disconnected groups denoted modules, core/periphery structures and other. Moreover, groups coincide with the intrinsic properties of the underlying software projects, which promotes practical applications in software engineering.