ir william halsted introduced a german-style residency training system with an emphasis on graded responsibility at Johns Hopkins Hospital in 1889. 1 This system remains the cornerstone of surgical training in North America more than a century later. However, advances in educational theory, as well as mounting pressures in the clinical environment, have led to questions about the reliance on this approach to teaching technical skills. Those pressures include a move toward a shorter workweek for residents 2,3 and an emphasis on operating room efficiency, both of which diminish teaching time. Yet the patients in our teaching hospitals are generally much sicker and have more complex problems than in times past. The increasing complexity of cases and a greater emphasis on mitigating medical error limit a faculty's latitude in assisting residents with technical procedures. Sheer volume of exposure, rather than specifically designed curricula, is the hallmark of current surgical training. 4 But as opportunities for learning through work with "real" patients have diminished, interest in laboratories with formal curricula, specifically designed to teach surgical skills, has increased dramatically. In this new model of surgical education, basic surgical skills are learned and practiced on models and simulators, with the aim of better preparing trainees for the operating room experience. 5-10 These new training techniques are based on established theories of the ways in which motor skills are acquired and expertise is developed. Fitts and Posner's three-stage theory of motor skill acquisition is widely accepted in both the motor skills literature and the surgical literature (Table 1). 11,12 In the cognitive stage, the learner intellectualizes the task; performance is erratic, and the procedure is carried out in distinct steps. For example, with a surgical skill as simple as tying a knot, in the cognitive stage the learner must understand the mechanics of the skillhow to hold the tie, how to place the throws, and how to move the hands. With practice and feedback, the learner reaches the integrative stage, in which knowledge is translated into appropriate motor behavior. The learner is still thinking about how to move the hands and hold the tie but is able to execute the task more fluidly, with fewer interruptions. In the autonomous stage, practice gradually results in smooth performance. The learner no longer needs to think about how to execute this particular task and can concentrate on other aspects of the procedure. This model has obvious implications for surgical training. The earlier stages of teaching technical skills should take place outside the operating room; practice is the rule until automaticity in basic skills is achieved. This mastery of basic skills allows trainees to focus on more complex issues, both technical and nontechnical, in the operating room. To return to the example of knot tying, the learner who still