An Argument Against Presenting Interval Quantifications as a Surrogate for the Value of Evidence

• NCJ Number: 255190
• Author(s): Danica M. Ommen; Christopher P. Saunders; Cedric Neumann
• Date Published: September 2016
• Length: 5 pages
• Grant Number(s): 2014-IJ-CX-K088
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored); Program/Project Description
• Award: Foundational Research into the Quantification of the Value of Forensic Evidence for Complex Evidential Forms arising from Impression and Pattern Evidence

Annotation

In this article, the authors argue that interval quantifications for the value of evidence should not be used directly in the Bayesian decision-making process to determine the support of the evidence for one of two competing hypotheses.

Abstract

In the various forensic science disciplines, recent analytical developments paired with modern statistical computational tools have led to the proliferation of ad hoc techniques for quantifying the probative value of forensic evidence. Many legal and scientific scholars agree that the value of evidence should be reported as a likelihood ratio or a Bayes Factor. Quantifying the probative value of forensic evidence is subjected to many sources of variability and uncertainty. There is currently a debate on how to characterize the reliability of the value of evidence. Some authors have proposed associating a confidence/credible interval with the value of evidence assigned to a collection of forensic evidence. (publisher abstract modified)