INTRODUCTION TO COMPUTER-AIDED DESIGN OF USER INTERFACES l 2 Jean Vanderdonckt and Angel Puerta ,3 Jlnstitut d'Administration et de Gestion - Universite catholique de Louvain Place des Doyens, 1 - B-1348 Louvain-la-Neuve (Belgium) vanderdonckt@gant,ucl. ac,be , vanderdoncktj@acm,org Web: http://www. arpuerta. com JKnowledge Systems Laboratory, Stanford University, MSOB x215 Stanford, CA 94305-5479, USA puena@camis. stanford. edu 3RedWhaie Corp. , 277 Town & Country Village Palo Alto, CA 94303, USA puerta@ redwhale. com Web: http://www. redwhale. com Computer-Aided Design of Vser Interfaces (CADUI) is hereby referred to as the particular area of Human-Computer Interaction (HCI) intended to provide software support for any activity involved in the development life cycle of an interactive application, Such activities namely include task analysis, contextual inquiry [l], requirements definition, user-centred design, application modelling, conceptual design, prototyping, programming, in- stallation, test, evaluation, maintenance, Although very recently addressed (e. g. , [3]), the activity of re-designing an existing user interface (VI) for an interactive application and the activity of re-engineering a VI to rebuild its underlying models are also considered in CADVI. A fundamental aim of CADVI is not only to provide some software sup- port to the above activities, but also to incorporate strong and solid meth- odological aspects into the development, thus fostering abstraction reflection and leaving ad hoc development aside [5,7]. Incorporating such methodo- logical aspects inevitably covers three related, sometimes intertwined, facets: models, method and tools.