Is the UML appropriate for Interaction Design?

In this paper we argue that while there exist several approaches to modeling user interfaces of web ap- plications when adopting a Model Driven Devel- opment methodology, too little attention is payed to the actual abstract behavior of the interface. In the UML-IDEA approach we adopt the UML as a modeling language and start from a very abstract view of the UI specified in terms of state machines. We claim that expressivity of the language is suf- ficient to capture, even at the abstract level, many usability problems. At the same time, transforma- tions of models into more concrete levels generate executable code and test cases, wireframe proto- types and representations suitable also for accessi- bility assessments. In this way usability and acces- sibility investigations could be carried out during conceptual design.