Signature Authentication by Forensic Document Examiners

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.

Forgery Quality and Its Implications for Behavioral Biometric Security

“…We caution the reader that the proficiency of professional document examiners compared to that of laypersons in detection forgeries remains a controversial topic (see for example, [6], [31]). Indeed, while recent studies [11], [12] seem to indicate that a well-trained subset of the population can perform significantly better than chance at this task, these results are still being openly debated. For that reason, we primarily use our analysis of human judges as yet another indication of the importance of using strong forgers for evaluation purposes.…”

The Probability to Prove the Distinguishing Handwriting Between Natural and Disguise of Egyptian Arab Writing

“…This means that when participants were willing to give an opinion on which of a pair of handwriting samples was disguised, the FDEs have a significantly higher correct rate than laypeople (95.66% correct called compared to 87.84%, t = 3.86, df = 19, p = 0.001) [7]. A prototype of a handwriting pair written by student's female person.…”

A Study to Determine the Inheritance Pattern of Characteristics of Handwriting between Parents and Off-springs

“…However, there is only 14% similarity in the pressure applied while writing. Likewise, the loop of the letter "e" (18%) and baseline (28%) also show a low level of similarity [11][12][13][14].…”