A design space for user interface composition

Modern user interfaces are highly dynamic and interactive. They often compose in various ways user interface components. Thus, there is a need to understand what can be composed in user interfaces and how. This chapter presents a design space for user interface composition. The design space consists of five dimensions addressing aspects ranging from the UI abstraction level involved, the granularity of UI elements involved, the UI aspects that are affected by it, the time when such a composition occurs, and the type of web services involved. The design space is then analyzed with respect to the capabilities of the ConcurTaskTrees and MARIA languages in order to show how it is possible to compose user interfaces at various abstraction levels. In order to provide a deeper insight, in the paper, we also present a number of excerpts for several composition examples.