NCJ Number
145258
Journal
Law and Human Behavior Volume: 17 Issue: 5 Dated: (October 1993) Pages: 569-595
Date Published
1993
Length
27 pages
Annotation
This study explored how mock jurors assessed eyewitness credibility and integrated these assessments with judgments of probative value in simple, corroborating, contradicting, and facilitating inference structures.
Abstract
The first experiment examined how jurors evaluated eyewitness credibility in different inference structures in a complex, realistic case and how they integrated different evidence items. The second experiment sought to determine what variables affected eyewitness credibility. The third experiment determined whether subjects used an additive or an averaging version of the decision rule based on p (event/guilt) weighted by credibility. Subjects in all experiments, introductory psychology students, listened to an audiotape of a fictional theft trial. In the first experiment, contrary to prior research, the amount of detail in eyewitness testimony did not influence perceived credibility. In addition, a normative Bayesian rule poorly described subjects' integration of evidence. A rule that combined p weighted by credibility better described judgments. The second experiment showed that perceived eyewitness credibility was affected by the credibility of a second witness, and the nature of the effect depended on the type of inference structure. The third experiment showed that an additive version of the decision rule characterized judgments of guilt better than an averaging version. 48 references, 3 tables, and 3 figures