How do people evaluate the credibility of confident but fallible sources?
In an era of overconfident communicators, this research informs models of how human and artificial systems convey confidence and manage uncertainty.
At the Institute of Communication and Cognition Sciences, I designed and implemented two online experiments (Qualtrics), recruited participants (Prolific), ran data collection, and analyzed the results.
Participants judged the testimony of two fictional witnesses: one confident, one unconfident. The scenarios varied whether the confident speaker was (1) inaccurate but well-justified, or (2) accurate but weakly justified.
Confidence only backfired when it exceeded the supporting evidence, even if the information itself was accurate.
This principle illustrates how human and AI systems can signal certainty responsibly, shedding light on the mechanisms behind AI "hallucinations".
Invited speaker, TRUEDEM (Trust in European Democracies) Webinar Series (2025)
Presented at numerous conferences, among them Experiments in Linguistic Meaning (ELM) 2
Published as part of the special issue “Trust and Trustworthiness: individual and institutional dimensions” in Philosophical Psychology (2024)
Published in Ars interpretandi (2023), discussing the implications for legal testimony
I used a Generalized Linear Mixed Model to analyze changes in binary choices over time, and a Cumulative Link Mixed Model to analyze changes in ordinal credibility ratings, accounting for repeated measures.