Scaling up Search Engine Audits: Practical Insights for Algorithm Auditing

TL;DR

This paper discusses scalable methods for auditing search engine algorithms using virtual agents, providing practical insights, methodological guidance, and demonstrating successful large-scale experiments across multiple search engines.

Contribution

It offers a comprehensive methodology, lessons learned, and recommendations for conducting large-scale search engine audits with virtual agents, enhancing research transparency and replicability.

Findings

Virtual agents enable systematic, cost-effective search engine audits.

Successful deployment across diverse search engines and regions.

Strategies to improve audit quality and reliability.

Abstract

Algorithm audits have increased in recent years due to a growing need to independently assess the performance of automatically curated services that process, filter, and rank the large and dynamic amount of information available on the internet. Among several methodologies to perform such audits, virtual agents stand out because they offer the ability to perform systematic experiments, simulating human behaviour without the associated costs of recruiting participants. Motivated by the importance of research transparency and replicability of results, this paper focuses on the challenges of such an approach. It provides methodological details, recommendations, lessons learned, and limitations based on our experience of setting up experiments for eight search engines (including main, news, image and video sections) with hundreds of virtual agents placed in different regions. We demonstrate the successful performance of our research infrastructure across multiple data collections, with diverse experimental designs, and point to different changes and strategies that improve the quality of the method. We conclude that virtual agents are a promising venue for monitoring the performance of algorithms across long periods of time, and we hope that this paper can serve as a basis for further research in this area.