GUIDE: Creating accessible TV applications
Objective. In this paper we describe a novel adaptive accessibility framework for Hybrid TV platforms and the user-centred approach that is being used in its design. It integrates various types of user interface (UI) technologies, supports multimodal interaction, performs adaptation to individual needs and limitations of elderly users, and uses virtual user simulation for efficient UI testing in the design process. Main content. Digital TV has gained importance as an interactive and personalized media terminal, now combining traditional broadcast content with internet and legacy web services. However, the elderly face problems when using these services. The availability of accessible user interfaces and supporting software is very limited. For developers, user-centred design and provision of accessible user interfaces is expensive and time-consuming. In order to support developers we propose a solution comprising of (1) an adaptive software framework and (2) a set of tools to support development, including a simulation tool. The software framework can be integrated in existing applications and provides an API for developers to automatically perform adaptation of user interface input and output data. The simulation tool is able to render simulated perception of elderly users for the developers. Results. The approach presented relies on user modeling identifying the most relevant impairment configurations among users in comprehensive trials. Using the simulation tool, developers can iteratively make modifications in order to optimize their application's UI. Simulation considers models for perception, cognition and motor functions. The resulting design is then executed in a framework where first time users are characterized by a procedure which measures their individual abilities. A user model instance is then the foundation of a multi-modal adaptation module performing input fusion and output fission for various combinations of user interface technologies considering the user impairments and high level events describing the interaction context. As a result, the system selects proper combinations and configurations of available input and output modalities. Conclusion. For elderly users, accessible ICT can make much more of a difference in living quality, by enabling and simplifying participation and inclusion in their surrounding communities. By supporting TV application developers through a design time simulation tool, and a run time adaptive framework, we lay the basis to drastically improve overall accessibility of these applications.