In April 1981 Xerox announced the 8010 Star Information System, a new personal computer designed for office professionals who create, analyze, and distribute information. The Star user interface differs from that of other office computer systems by its emphasis on graphics, its adherence to a metaphor of a physical office, and its rigorous application of a small set of design principles. The graphic imagery reduces the amount of typing and remembering required to operate the system. The office metaphor makes the system seem familiar and friendly; it reduces the alien feel that many computer systems have. The design principles unify the nearly two dozen functional areas of Star, increasing the coherence of the system and allowing user experience in one area to apply in others.