Audit seniors from 2 international public accounting firms participated in 2 experiments designed to test hypotheses derived from legal theorist Jeremy Bentham's (1827) theory of persuasiveness of evidence. Statistically, significant results in the predicted direction were found for 6 characteristics of evidence: 1. amount of evidence - number of tests, 2. dispersion of estimates, 3. composition of the evidence set, 4. source reliability, 5. directness of evidence and 6. deviations from expectations. Knowledge of the characteristics that make evidence persuasive could be useful in developing theory-based models of professional judgment, expert systems for evaluating evidence, and improved frameworks for educating novices.