There is perhaps no facet of modern society where the influence of computer automation has not been felt. Flight management systems for pilots, diagnostic and surgical aids for physicians, navigational displays for drivers, and decision-aiding systems for air-traffic controllers, represent only a few of the numerous domains in which powerful new automation technologies have been introduced. The benefits that have been reaped from this technological revolution have been many. At the same time, automation has not always worked as planned by designers, and many problems have arisen--from minor...