Proficiency of professional document examiners in writer identification

A comprehensive writer identification test was designed and administered to a group of professional document examiners and to a control group of nonprofessionals. The professional group consisted of seven document examiners from the Federal Bureau of Investigation. The control group consisted of ten graduate students in the areas of engineering and business. The main finding is that the professional document examiners per formed significantly better than the members of the control group. The hypothesis that professionals and nonprofessionals are equally proficient in performing writer identification was found via the Kruskal-Wallis test to have probability of less than 0.001. These findings give indication that handwriting identification expertise indeed exists, and calls into question the conclusions of previous studies in this area.