An engineering psychologist studies how people work best with machines. Develops principles relating human behavior to environments and systems within which people work and live, such as how can a computer be designed to prevent eye strain, what assembly line arrangement makes production most efficient, or what is a reasonable workload. Most work in industry, but may also work for government, and may be called human factors specialists. Provides input in the development/use of man-machine systems to obtain optimum efficiency, and advises on human factors to be considered in design of man-machine systems, military equipment and industrial products. Helps solve such problems as gauging number and type of workers required to operate machines, allocation of functions, and arrangement of work sites. Develops training methods and materials for use by equipment and system designers. Requires a doctorate degree.