The Capability of Code Review as a Communication Network

TL;DR

This paper formalizes and empirically tests the theory that code review acts as a communication network, demonstrating its capacity for wide and rapid information diffusion across different systems.

Contribution

It provides the first empirical validation of code review as a communication network by quantifying information spread in open and closed-source systems.

Findings

Open-source code reviews spread information faster.

Closed-source code reviews reach more participants.

Code review enables wide and fast information diffusion.

Abstract

Background: Code review, a core practice in software engineering, has been widely studied as a collaborative process, with prior work suggesting it functions as a communication network. However, this theory remains untested, limiting its practical and theoretical significance. Objective: This study aims to (1) formalize the theory of code review as a communication network explicit and (2) empirically test its validity by quantifying how widely and how quickly information can spread in code review. Method: We replicate an in-silico experiment simulating information diffusion -- the spread of information among participants -- under best-case conditions across three open-source (Android, Visual Studio Code, React) and three closed-source code review systems (Microsoft, Spotify, Trivago) each modeled as communication network. By measuring the number of reachable participants and the minimal topological and temporal distances, we quantify how widely and how quickly information can spread through code review. Results: We demonstrate that code review can enable both wide and fast information diffusion, even at a large scale. However, this capacity varies: open-source code review spreads information faster, while closed-source review reaches more participants. Conclusion: Our findings reinforce and refine the theory, highlighting implications for measuring collaboration, generalizing open-source studies, and the role of AI in shaping future code review.