This study examines the use of statistical evidence in the trial process. Statistical evidence, such as DNA analyses, may give rise to judgment errors, and the study investigates the conditions under which fact-finders will be most influenced by this evidence. The first phase of the study examines the use and characterization of statistical evidence in recent trial data in order to identify and analyze central points of confusion and judgment errors such as the source probability error and the numerical conversion error. The second phase is a pilot study to conduct a series of experiments with mock jurors and practicing judges to examine how the context, manner, and vividness of quantitative testimony from experts affect fact-finder's probabilistic judgment and verdicts. The study will provide the empirical foundation for: (1) testing the strengths and weaknesses of theories about intuitive quantitative reasoning; (2) understanding of the nature and significance of misleading claims about statistical trace evidence; (3) developing standards for quantitative expert testimony; and (4) suggesting appropriate quantitative training for law curricula.
