Seventeen FDE's from five Australian and New Zealand government forensic laboratories participated in the study. Fourteen of the FDE's were fully qualified and had been practicing handwriting examination between 3.5 and 20 years; 3 were trainees with 1-3 years pre-qualified training. Thirteen individuals with no document examination experience or any prior professional association with handwriting examination were used as the control group. The practicing FDE's and control subjects were asked to examine 150 questioned signatures and provide opinions as to whether each signature was genuine or simulated; in cases in which it was not possible to differentiate between the two categories, an "inconclusive" opinion was an option. Findings showed that FDE's were statistically better than the control group at accurately determining the genuineness of questioned signatures. The FDE group made errors (by calling a genuine signature simulated or by calling a simulated signature genuine) in 3.4 percent of their opinions; and 19.3 percent of the control group's opinions were erroneous. The FDE group gave significantly more inconclusive opinions than did the control group. The FDE's opinions indicated that more correct opinions were rendered regarding simulated signatures, and more inconclusive opinions were assigned to genuine signatures. Further, when the complexity of a signature was taken into account, FDE's rendered more correct opinions on high complexity signatures than on signatures of lower complexity. There was a wide range of skill among FDE's, but no significant relationship was found between the number of years FDE's had been practicing and their correct, inconclusive, and error rates. 5 tables, 2 figures, and 17 references