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Using subsampling to estimate the strength of handwriting evidence via score-based likelihood ratios

NCJ Number
Forensic Science International Dated: March 10, 2012
Date Published
March 2012
0 pages

This project illustrated one possible approach to estimating a likelihood ratio in comparative handwriting analysis.


The likelihood ratio paradigm has been studied as a means for quantifying the strength of evidence for a variety of forensic evidence types. Although the concept of a likelihood ratio as a comparison of the plausibility of evidence under two propositions (or hypotheses) is straightforward, several issues arise when considering how to go about estimating a likelihood ratio. The novelty of the proposed approach relies on generating simulated writing samples from a collection of writing samples of a known source to form a database for estimating the distribution associated with the numerator of a likelihood ratio. This approach is illustrated using documents collected from 432 writers under controlled conditions. (publisher abstract modified)

Date Published: March 1, 2012