Discusses the design of computer applications, focusing on understanding design representations--what makes design representations work, and how, in different contexts. Examines the place of various types of representation (e.g., formal notations, models, prototypes, scenarios, and mock-ups) in design and the role of formalisms and representations…

Interacting cognitive subsystems (ICS) is proposed as a unified cognitive theory that can be used as the basis for representations in human-computer interaction, and two approaches based on the theory are described: one entails the description of cognitive task models, and the other entails the production of less complete diagrammatic notations.…