Beyond models and metaphors: visual formalisms in user interface design

The user interface has both syntactic functions-supplying commands and arguments to programs-and semantic functions-visually presenting application semantics and supporting problem solving cognition. The authors argue that though both functions are important, it is time to devote more resources to the problems of the semantic interface. Complex problem solving activities, e.g. for design and analysis tasks, benefit from clear visualizations of application semantics in the user interface. Designing the semantic interface requires computational building blocks capable of representing and visually presenting application semantics in a clear, precise way. The authors argue that neither mental models not metaphors provide a basis for designing and implementing such building blocks, but that visual formalisms do. They compare the benefits of mental models, metaphors and visual formalisms as the basis for designing the user interface, with particular attention to the practical solutions each provides to application developers