Simulation is a methodology, not a technology, although technology plays a significant role in some forms of simulation. Its utility is well documented in training people who work in jobs where the risk to human life is high: Commercial aviation, aerospace, nuclear power, and the military all routinely simulate potentially life-threatening situations and allow their trainees to practice management of these situations without risk to themselves or others. Certain types of simulation-based training have also been used in medicine; learning chest compressions on CPR mannequins and interviewing standardized patients are 2 examples. In general, however, medicine has lagged behind other industries and professions in using this methodology to improve human performance.