Episode 39: 2018 IPTES: Just Bayesian Brawl

• NCJ Number: 251660
• Author(s): Steven Lund; Hari Iyer; Cedric Neumann; Daniel Ramos; Alex Biedermann
• Date Published: April 2018
• Length: 2 pages
• Grant Number(s): 2016-MU-BX-K110
• Agencies: NIJ-Sponsored
• Publication Type: Report (Technical Assistance); Report (Grant Sponsored); Instructional Material (Programmed); Conference Material

Annotation

This online audio (podcast) covers the discussion by members of a panel on Statistical Approaches to Forensic Interpretation, which was part of a 2018 symposium on various statistical topics in forensic science.

Abstract

The five panel members were Steven Lund, Hari lyer, Cedric Neumann, Daniel Ramos, and Alex Biedermann. Each of the five panel members gave presentations at the symposium, which focused on statistical analysis that yields likelihood ratios for the accuracy of decisions made by forensic experts in their analysis of evidence. The topics of these presentations included what is expected from expert witnesses, challenges faced by experts in explaining forensic evidence to triers of fact, the use of similarity measures (scores) to quantify the weight of forensic evidence, the evidential value of multivariate data, and the "anatomy" of forensic identification decisions. For the panel discussion accompanied by questions and comments from the audience, the five members focus on how statistical analysis that produces likelihood ratios for evidentiary decisions can be explained to jurors so they can properly weigh the reliability of the forensic expert's evidentiary conclusions. Among the suggestions discussed are having multiple forensic analysts compute the likelihood ratio for their evidentiary decisions after each has examined the same evidence. Averaging the likelihood ratios to be presented in testimony might give jurors stronger ground for weighting the expert's conclusion. Another suggestion was to have improved transparency about statistical methods used in measuring likelihood ratios for forensic evidentiary conclusions. Each of the five presentations given by the panelists at the symposium are accessible online from this web page.