Upside-downs and Algorithms-Computational Formalisms and Theory

The theory of computation predates digital computers themselves, as mathematicians pondered the limits of human reasoning and computation. There are a number of aspects of this interplay among computation, mathematics, and the human-computer interface. First, understanding the raw material is essential in all design. Part of the material of human-computer interaction (HCI) is the computer itself. Theoretical and formal aspects of computing can help understand the practical and theoretical limits of computer systems. Second, diagrams, drawings, and models are an integral part of the design process. Formal notations can help sketch the details of interaction, not just the surface appearance of an interactive system, and thus helps analyze and understand its properties before it is built. This is the area that is typically called formal methods within HCI. Third, various techniques from mathematics-simple counting to sophisticated equations may be used to reason about specific problems in HCI.