Consistent modelling of users , devices and environments in a ubiquitous computing environment

This paper describes the use of an accretion/resolution user modelling representation to model people, places and things. We explain the motivation for the key properties of the representation, especially those of particular importance for ubiquitous computing: firstly, for flexibility in interpreting the typically noisy and potentially conflicting evidence about users’ locations; secondly, to support users in scrutinising their user model, the processes that determine its contents and the way that it is used in the ubiquitous computing environment. A novel and important aspect of this work is our extension of the representation beyond modelling just users, using it also to represent the other elements such as devices, sensors, rooms and buildings. We illustrate our approach in terms of models we have been building for a system which enables users to gain personalised information about the sensors and services in a ubiquitous computing environment. We report experiments in modelling user location and activity in such an environment, showing how our approach supports different spatial and temporal granularity in location modelling and tests of the speed of determining the values of these aspects of the user model.