Speaker Series – Andrew Guess

The Centre for the Study of Democratic Citizenship presents:
How do social media algorithms affect platform use, attitudes and behavior?
Andrew Guess (Princeton, États-Unis)
When: Octobre 6, 2025, 3 – 5p.m.
Where: Université de Montréal, Pavillon Lionel-Groulx – C-2059, 3150 rue Jean-Brillant Montréal (Québec) H3T 1N8
Zoom link :
https://umontreal.zoom.us/j/81870106921?pwd=WDJIdHprOGVzakFMMFcrRE9IblV4Zz09
Meeting ID : 818 7010 6921
Password : 853729
Policymakers and the public are increasingly interested in the effects of social media algorithms on society. In this talk, I outline some of the challenges this topic poses to researchers. I then introduce an approach to studying these systems’ effects on individuals: a large-scale collaboration with Meta during the 2020 U.S. presidential campaign. Focusing on experiments designed to change how posts were ranked in users’ feeds, I explore how our treatments altered the types of content users saw. Among the categories we analyze are political news, posts from like-minded (vs. cross-cutting) sources, and posts from sources deemed untrustworthy. Finally, I discuss the effects of our treatments on individuals’ political behavior, knowledge, and attitudes.
This series is sponsored by the Centre for the Study of Democratic Citizenship, which is funded by the Fonds de recherche du Québec – Société et culture (FRQSC).