This book provides a broad overview of the contributions of experimental research in psychology and related disciplines to the domain of human-computer interaction. Four major topics are considered. The first deals with the presentation of visual information and basic aspects of visual information processing. Some relevant applications are also illustrated in the domains of texts and visual presentation of statistical information. The second major topic is concerned with the representation of knowledge. The interaction between man and machine is most effective if both components have an adequate representation of knowledge. Several techniques of representation are shown, and the compatibility between human representation and machine representation is discussed. The development of expert systems will in many respects change the nature of the interaction between man and machine in artificial intelligence. In the third part, future developments, the current state of expert systems as compared with human experts and the characteristics of productions systems which are so prominent in most expert systems are all discussed. Finally, some features of interaction with systems are reviewed, including the ergonomic value of key boards and advanced input modes like handwritten text and speech. Procedures for searching for information in large databases and for the use of natural language in the interaction between man and machine are increasingly important.