In software engineering transformational development is a paradigm consisting in the progressive refinement of abstract models into concrete models, until program code. This thesis applies transformational development concepts to User Interfaces (UIs). It enlarges the paradigm of transformational development by defining a methodology allowing the realization of various types of development paths (e.g., forward engineering, reverse engineering, context of use adaptation) in order to realize multi-path development, we propose an ontology of concepts defining various viewpoints that can be maintained on a UI system. Viewpoints are hierarchically structured depending on their level of abstraction. They describe user tasks, classes of objects, presentational and behavioral aspects of UIs, context of use, and a set of mappings between these representations. The underlying mathematical formalism of our ontology being a graph structure (directed, identified, labeled, constrained, and typed graphs), we transform one viewpoint into another by the application of conditional graph rewriting rules gathered in graph grammars. These enable us expressing a wide variety of transformational heuristics so as to be able to express multiple development paths. Ontology and transformations may be stored in an XML format called UsiXML (User interface eXtensible Markup Language) allowing the dissemination, the capitalization, and the consolidation of UI specifications and transformation catalogs.(PhD in Management Sciences, option "Information Systems") -- UCL, 200
