The professional expertise of physicians is under closer scrutiny-by the profession, the public, and the government-than is any other profession. In the past, it was our manual competence that drew the most attention: a slip of the knife, a surgical clamp left inside, misapplied obstetric forceps, or a needle pushed someplace it didn’t belong. Cognitive expertise was of less importance, at least judging by the relative prices of malpractice insurance for the “procedural” (e.g., surgery and obstetrics) versus “cognitive” (e.g., internal medicine, pediatrics, neurology, and psychiatry) medical specialties. However, the increasing attention on health care costs and outcomes is being manifested as increased interest in the cognitive activities of all physicians. More and more, the decisions that we make are being analyzed in terms of their cost-effectiveness, usefulness, safety, and, of course, appropriateness.