3 Susan McKeever Juan Ye Lorcan Coyle Simon Dobson 2008 R. Mayrhofer, A Quigley, J. Kay, G. Kortuem, S. Ardon, E. Rukzio, A. Vande Moere, G. Abowd, K. Suginuma Late Breaking Results - Adjunct Proceedings of the 6th International Conference on Pervasive Computing Sydney, Australia OCG 1-4 09.05.2008 978-3-85403-236-6 context-aware, uncertainty, pervasive computing, ubiquitous computing Context-aware systems typically use data sensed from the environment to drive adaptive behaviour. Sensed data is inherently imprecise and uncertain; in addition, new uncertainties are introduced when sensed data is fused with other data to infer context at the more abstract level of situations. We present an uncertainty model which aggregates context uncertainty and provides mechanisms to capture uncertainty at situation level. We demonstrate the application of the model in a sample scenario using an experimental data set.