This completely revised edition, of the Handbook of Human-Computer Interaction, of which 80% of the content is new, reflects the developments in the field since the publication of the first edition in 1988. The handbook is concerned with principles for design of the Human-Computer Interface, and has both academic and practical purposes. It is intended to summarize the research and provide recommendations for how the information can be used by designers of computer systems. The volume may also be used as a reference for teaching and research. Professionals who are involved in design of HCI will find this volume indispensable, including: computer scientists, cognitive scientists, experimental psychologists, human factors professionals, interface designers, systems engineers, managers and executives working with systems development. Much of the information in the handbook may also be generalized to apply to areas outside the traditional field of HCI.