Measuring the Frequency Occurrence of Handwriting and Hand-Printing Characteristics

• NCJ Number: 250539
• Author(s): Mark E. Johnson; Thomas W. Vastrick; Michéle Boulanger; Ellen Schuetzner
• Date Published: January 2016
• Length: 85 pages
• Grant Number(s): 2010-DN-BX-K273
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored); Program/Project Description

Annotation

This project's objectives were to develop statistically valid frequency-occurrence proportions for selected characteristics of handwriting and hand-printing based on specimen samples representative of the U.S. population, so as to provide practitioners of forensic document examination with a statistical basis for reliability and measurements validity, as well as to provide courts with the requested supporting data.

Abstract

One of the basic axioms of handwriting comparison is that no two writers use the exact same set of handwriting characteristics. The database created by this research and the resulting frequency occurrence proportions provide the forensic and judicial communities with some empirical data with which to assess this axiom; for example, examiners can use the project data as part of their estimation of confidence designated by the National Research Council Report (2009). The frequency proportions developed in this project potentially can be used to provide these categories with supporting calculations. This study is not the first on the subject of frequency occurrence in handwriting. The specific approach in collecting samples that match the U.S. demographics provides unique insight and substantive data on the quantitative relationship between the presence/absence of readily identifiable features and key demographic factors as noted by Huber and Headrick (age, gender, ethnicity, education, location of second/third grade schooling, and handedness (right or left) while controlling for other factors, such as temporal state and geographic locations. The original set of specimens collected from a wide spectrum of participants provided an initial large collection that was eventually pared down to achieve what is considered a representative sample from the entire target population. 41 tables, 5 figures, and 53 references