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ABSTRACT
One challenge in software engineering is the development of smart environments that help users to intuitively accomplish their tasks. The ideal smart environment dynamically manages a diverse collection of devices, is accessible by multiple users and effectively supports the users' tasks. The design of smart environments relies on detailed models of devices, users and their tasks.
In this paper, we present our modelling language "CTML" specifically developed for smart environments. We demonstrate how the language was designed and how it was used for usability evaluations in a virtual smart environment. We then discuss the importance of "task migrateability" - a usability principle often neglected by contemporary smart environments. We argue that the proper implementation of this usability criterion can improve the usability of smart environments. Finally, we investigate how tangible user interfaces are related to smart environments and how this interaction technique can be used to support task migrateability.
Keywords
Supportive user interface, task migratability, smart environment
INTRODUCTION
One of the starting points for the development of new kinds of systems assisting users was Marc Weiser's vision of ubiquitous computing [22]. According to this vision supporting devices are weaving themselves automatically into everyday life in such a way that allows people to concentrate on their tasks.
Such an environment is considered to be smart. It tries to analyze the user's behaviour and to provide appropriate assistance.
In recent years, such systems made their way from research to industrial applications. Let us consider the domain of meeting rooms where the performance of workshops has to be supported. Within this context a presenter should be able to concentrate on his talk, while the smart environment (SE) intervenes by adjusting the projector, loading the necessary files and capturing audiovisual data for meeting documentation if needed. In the best case no direct interaction is necessary.
Figure 1 gives a visual impression of our laboratory where experiments are performed.
Implicit interaction like going to the presentation area is enough to present the slides of the speaker. Experiences show [13] that the quality of support can be increased if some information is given to the system. Most important are the tasks the users want to perform within the environment.
Task models are an appropriate starting point for interactive processes...