Gas Man is an educational computer simulation program. The goal of the program is for the user to learn the theory and application of inhalation anesthesia uptake and distribution. The program and accompanying text are designed to be used by medical students, pharmacy students, anesthesia residents, nurses, practicing anesthesiologists, and medical equipment technicians and engineers. After using the program, the learner should understand the time course of patient response to inhalation anesthesia. He should know the factors which influence patient response and be able to predict their impact in specific situations. The key to Gas Man's success are: A well-defined and valid educational goal, teaching anesthesia uptake and distribution. An identifiable and testable set of educational objectives. A specific set of learner tasks to achieve those objectives, the actual simulation exercises. The appropriate educational medium, computer simulation and graphics. Effective software implementation, the Gas Man Program.