  Background: As a core practice in software engineering, the nature of code
review has been frequently subject to research. Prior exploratory studies found
that code review, the discussion around a code change among humans, forms a
communication network that enables its participants to exchange and spread
information. Although popular in software engineering, there is no confirmatory
research corroborating this theory and the actual extent of information
diffusion in code review is not well understood.
  Objective: In this registered report, we propose an observational study to
measure information diffusion in code review to test the theory of code review
as communication network.
  Method: We approximate the information diffusion in code review through the
frequency and the similarity between (1) human participants, (2) affected
components, and (3) involved teams of linked code reviews. The measurements
approximating the information diffusion in code review serve as a foundation
for falsifying the theory of code review as communication network.
