ISSN: 0022-1198
CODEN: JFSCA
Page Count: 5

Signature Authentication by Forensic Document Examiners
Fielding, G
Data Fusion Laboratory, Electrical and Computer Engineering Department, Drexel University, PA

Gummadidala, K
Data Fusion Laboratory, Electrical and Computer Engineering Department, Drexel University, PA

Kam, M
Data Fusion Laboratory, Electrical and Computer Engineering Department, Drexel University, PA

Conn, R
RABA Technologies, Inc., MD

(Received 10 May 1999; accepted 29 September 2000)

Abstract

We report on the first controlled study comparing the abilities of forensic document examiners (FDEs) and laypersons in the area of signature examination. Layersons and professional FDEs were given the same signature-authentication/simulation-detection task. They compared six known signatures generated by the same person with six unknown signatures. No a priori knowledge of the distribution of genuine and nongenuine signatures in the unknown signature set was available to test-takers. Three different monetary incentive schemes were implemented to motivate the laypersons.

We provide two major findings: (i) the data provided by FDEs and by laypersons in our tests were significantly different (namely, the hypothesis that there is no difference between the assessments provided by FDEs and laypersons about genuineness and nongenuineness of signatures was rejected); and (ii) the error rates exhibited by the FDEs were much smaller than those of the laypersons. In addition, we found no statistically significant differences between the data sets obtained from laypersons who received different monetary incentives.

The most pronounced differences in error rates appeared when nongenuine signatures were declared authentic (Type I error) and when authentic signatures were declared nongenuine (Type II error). Type I error was made by FDEs in 0.49% of the cases, but laypersons made it in 6.47% of the cases. Type II error was made by FDEs in 7.05% of the cases, but laypersons made it in 26.1% of the cases.

Keywords:
forensic science, questioned document examination, signature, validation, handwriting

Paper ID: JFS15062J
DOI: 10.1520/JFS15062J
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