Computerized assistance to clinicians during physician order entry can provide protection against medical errors. However, computer systems that provide too much assistance may adversely affect training of medical students and residents. Trainees may rely on the computer to automatically perform complex calculations and create appropriate orders and are thereby deprived of an important educational exercise. An alternative strategy is to provide a critique at the completion of an order, requiring the trainee to enter the entire order but displaying an alert if an error is made. While this approach preserves the educational components of order-writing, the potential for errors exists if the computerized critique does not induce clinicians to correct the order. The goal of this study was to determine (a) the frequency with which errors are made by trainees in an environment in which renal dosing adjustment calculation for antimicrobials are done by the system after the user has entered an order, and (b) the frequency with which prompts to clinicians regarding these errors leads to correction of those orders.