1 Rapid Prototyping of Adaptable User Interfaces

User Interface Adaptation has been proposed in recent years as a means to achieve personalized accessibility and usability of user interfaces. Related user interface architectures, as well as a variety of related development method and tools, have also been elaborated. Admittedly, however, despite the recognized validity of the approach, which has been proved in practice in a series of prototype systems, the wider adoption and uptake of user interface adaptation approaches is still limited. One of identified obstacles is the complexity intrinsic in designing such interfaces, and the need of radically revising the current user interface design practice to account for (i) the alternative designs required for adaptation, (ii) the parameters involved in driving adaptations (i.e., selecting among alternatives at a given point during interaction), and (iii) the logic of adaptation at run-time. This paper proposes a two-fold tool-based support strategy for user interface adaptation development, based on: (i) an adaptation development toolkit and related widget library which directly embeds lexical level adaptations into common interactive widgets, and (ii) embedding such a library in a common integrated development environment, thus allowing designers to define and view alternative adaptations at design time, and create adaptable user interfaces through traditional prototyping. The above approach has been implemented in the domain of adaptable applications for older users, producing tools which are currently in use in the development of a large suite of interactive applications in various domains. The approach presented in this paper is claimed to be the first and so far unique supporting rapid prototyping of adaptable user interfaces, thus minimizing the divergence between typical development practices and user interface adaptation development. 1