Anikó Hannák
Associate Professor, Social Computing Group
University of Zurich
Anikó Hannák is an associate professor of computer science at the University of Zurich, where she works in the Social Computing Group on how search engines, online stores and job platforms rank people and products. She helped develop algorithm auditing as a research method, and her recent audits examine Google's AI Overviews and the product advice AI chatbots give shoppers.
Opening the Black Box
"These programs are a black box," Hannák told UZH Magazin in 2020. "We don't know how they function, and the companies don't disclose this information." Her answer, developed during her PhD at Northeastern University with Alan Mislove and David Lazer, was algorithm auditing: controlled experiments that reveal what a platform's ranking and recommendation systems do from the outside. Early audits measured the filter bubble effect on Google Search and online price discrimination. Asked whether probing platforms this way is legal, she said, "That's a complex question. It's against the terms of use, for sure."
Her studies of TaskRabbit, Fiverr and Stack Overflow found that women and Black workers were disadvantaged, and that the platforms' algorithms amplified the bias by learning from customer feedback. "Many trim their platforms to profit, and fairness falls by the wayside," she said. "In the analog world, discrimination is forbidden. The same rules have to apply online."
Auditing AI Answers and Shopping Advice
Hannák has carried the method into AI search. She co-authored an ICWSM 2026 audit of Google's AI Overviews and featured snippets on 1,508 baby care and pregnancy queries with Aleksandra Urman and Christo Wilson. Overviews appeared on 84% of the searches, disagreed with the featured snippet on the same page in 33% of cases, and included medical safeguards in only 11%.
She is also a co-author, with Konrad Kollnig and colleagues at Maastricht University, of a September 2026 audit of AI-generated product recommendations. Across 117 real shopping questions, each asked three times, ChatGPT stated a first-person preference in 79% of its product-recommending answers, against 7% for Gemini and 2% for AI Overviews. The products recommended shifted between repeats, and for the same question the ChatGPT and Gemini interfaces shared only 5.4% of their cited domains on average.
From Hungary to Zurich
Hannák is originally from Hungary. She joined the University of Zurich as an assistant professor of social computing at the start of 2020, after her doctorate at Northeastern's College of Computer and Information Science. She now holds an associate professorship in the Department of Informatics. She favors regulation that would require companies to open their algorithms to independent examination, and has pointed to EU research funding for platform monitoring as "a ray of hope."