Coping with uncertainty

This issue of IEEE Pervasive Computing focuses on building systems that deal with uncertainty. "Bayesian Filtering for Location Estimation" discusses how to reduce uncertainty in location estimates through statistical techniques. "Coping with Uncertainty in a Location-Based Game" discusses the impact of uncertainty in location sensing on user experience. It describes this impact in the context of a game and presents the authors' attempts to overcome the effects of this uncertainty. "Managing Context Information in Mobile Devices" describes a context management framework and API that simplifies the programming complexity of developing systems that handle uncertainty. Finally, "Using Trust for Secure Collaboration in Uncertain Environments" addresses the problem of uncertainty in the context of security. This uncertainty leads to risk, and the authors describe techniques to handle this risk.