Proceedings of the Annual Meeting of the Cognitive Science Society

The studies apply a Bayesian source credibility model to a legal setting to test epistemic influence of witnesstestimonies. The model amalgamates perceived witness trustworthiness and access to accurate information as independentelements that describe and predict the impact of the testimony of that particular witness.Across two studies, the model enjoys a good fit with observed posterior ratings of the likelihood of guilt (study 1: R2 = .867,study 2: R2 = .701). Study 1 (n = 101) employs different witness types and reports whilst study 2 (n = 102) employs differentwitness types, access to accurate information, and reports.The studies suggest the applicability of a Bayesian source credibility model in a legal setting to account for the impactof different witness types. We show that participants are sensitive to the type of witness and that different witnesses have apredictable impact on the perception of the testimony.