Résumé: Ultraportable mobile computers provide electronic assistance for environments and usage situations, where computer support up to now has not been feasible. For the first time, a true physical and cognitive integration of computer support into the everyday business of the real-world becomes possible, as envisioned in Mark Weiser's concept of ` ubiquitous computing a (Weiser, Communication of the ICM 1993, 36 (12): 75}85). However, although Handheld-PC, etc. today; already support a good deal of personal information management and basic access to distributed multimedia information services such as the World-Wide Web, they are still surprisingly difficult to use in ` full action a . Specifically, lengthy interaction sequences and the inability to find quickly that important piece of information which is embedded somewhere in the machine, makes using those devices sometimes a very disappointing experience. In this, paper, we outline a new approach to realizing an easy-to-use personal digital assistant systems, based on the concept of Situation Awareness. Using knowledge about task structures, situation dependencies, and task contexts, our concept allows a mobile assistant to proactively provide the right information at the right time and the right place, without intruding upon the users primary task: interacting with reality.

Langue: Anglais