Short Course Session 3: Quantitative Tools for Forensic Evidence

This event took place on April 23, 2021. A recording of the event can be found below. 

Session 3 Description:

Session 3: Quantitative Tools for Forensic Evidence is the third session in the three-session short course, Statistical Thinking for Forensic Practitioners. 

The National Academies report in 2009 and the PCAST report in 2016 encouraged consideration of quantitative approaches to assessing forensic evidence. In this session, we review two of the most often-suggested quantitative approaches, the two-stage approach and the likelihood ratio (Bayes factor) approach. Specific topics include:

• The two-stage approach to assessing forensic evidence
  • The role of statistical tests in assessing the similarity of two samples
  • Approaches for assessing the relevance of observed similarities
• Introduction to the likelihood ratio approach
  • Definition and interpretation of the likelihood ratio/Bayes factor
  • Possible applications to different types of evidence (DNA, trace, pattern)
  • Score-based likelihood ratios
  • Sensitivity of the likelihood ratio to modeling choices
• Results of studies comparing different ways of expressing source conclusions

Presenter:

Hal Stern
Co-Director of CSAFE
Interim Provost and Executive Vice Chancellor and Chancellor’s Professor, University of California, Irvine

About the Short Course:

Session 3 is the third session in the three-session short course, Statistical Thinking for Forensic Practitioners. Dr. Hal Stern and Dr. Alicia Carriquiry introduce fundamental concepts from probability and statistics –– motivated by forensic issues –– followed by a detailed investigation of how they apply to assess forensic evidence’s probative value. This short course will be held online in three sessions. Make sure to register for all three sessions because the content of later sessions builds on material from earlier sessions. Researchers, collaborators, and members of the broader forensics and statistics communities are encouraged to attend. Short course registrants who attend all sessions will receive a certificate of completion.

Here are the event links to the other sessions:

Session 1: Probability Concepts and their Relevance to Forensic Science

Session 2: Sampling, Statistics and the Status Quo