Quality Gatekeepers: Investigating the Effects of Code Review Bots on Pull Request Activities

Mairieli Wessel, Alexander Serebrenik, Igor Scaliante Wiese, Igor Steinmacher, Marco Aurélio Gerosa

Research output: Contribution to journalArticleScientificpeer-review

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Software bots have been facilitating several development activities
in Open Source Software (OSS) projects, including code review. However,
these bots may bring unexpected impacts to group dynamics, as frequently
occurs with new technology adoption. Understanding and anticipating such
effects is important for planning and management. To analyze these effects, we
investigate how several activity indicators change after the adoption of a code
review bot. We employed a regression discontinuity design on 1,194 software
projects from GitHub. We also interviewed 12 practitioners, including open-
source maintainers and contributors. Our results indicate that the adoption
of code review bots increases the number of monthly merged pull requests,
decreases monthly non-merged pull requests, and decreases communication
among developers. From the developers’ perspective, these effects are explained
by the transparency and confidence the bot comments introduce, in addition
to the changes in the discussion focused on pull requests. Practitioners and
maintainers may leverage our results to understand, or even predict, bot effects
on their projects.
Original languageEnglish
Article number108
Number of pages36
JournalEmpirical Software Engineering
Issue number5
Publication statusPublished - 2022


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