Handwriting changes under the effect of alcohol

Abstract

Document examiners are often faced with difficulties in evaluating handwriting by persons under the influence of alcohol. Although numerous articles are available on the subject of alcohol influence on handwriting quality, most of them were based on empirical data such as "few" or "increased", without any statistical evaluation. The aim of this research is to determine whether previous observations on reported effects of alcohol on handwriting are valid and to establish the predictability of observing specific effects. A total of 73 participants, who completed all steps of the experiment, were surveyed. Handwriting samples were taken before and after the consumption of alcohol. The test form, including criteria of prior studies used by document examiners, was evaluated with the help of a Olympus X-Tr stereo microscope, direct and oblique angle fighting and a video spectral comparator (VSC 2000). Measurements were done by means of digital caliper, statistics using repeated measures ANOVA, Pearson correlation, Pearson Chi square test, McNemar test and Wilcoxon signed rank test.