Interrupting users engaged in tasks typically has negative effects on their task completion time, error rate, and affective state. Empirical research has shown that these negative effects can be mitigated by deferring interruptions until more opportune moments in a user’s task sequence. However, existing systems that reason about when to interrupt do not have access to models of user tasks that...

Context-aware systems offer entirely new opportunities for application developers and for end users by gathering context information and adapting systems behavior accordingly. Several context models have been defined and various context-aware middleware has been developed in order to simplify the development of context-aware applications. Unfortunately, the development of an application by usin...

Current research in design of Context-Aware applications appears very technology focused, in particular software and sensor development and deployment rather than utilizing Human-Computer Interaction (HCI) principles such as task analysis to assist design of the applications. Developers specify what context-aware behavior to implement and determine what context information is needed based on in...

Growing number and complexity of context-aware systems requires a modeling framework suited for comparison of approaches. As a step towards modeling context-aware systems, we describe basic elements of such a framework. We introduce internal and external context information and define context models. We describe two conceptual architectures for context-aware systems and present their implicatio...

In the pervasive and mobile computing environment, workflow and context information are closely linked, workflow management system have to interact with a variety of sensors. Therefore, the design and development context-aware workflow applications become complex and difficult to migrate to other platforms. In order to simplify the development of context-aware workflow applications and enhance ...

In the past few years, context-aware computing has become one of the most promising topics of ubiquitous (pervasive) computing where computers are integrated and vanish in the background of users everyday activities. A context-aware system is a ubiquitous system, which is able to adapt its behavior automatically according to the gathered context information. However, due to the increasing compl...

Often context-aware systems consider the environment a defined element. Meanwhile reality is full of vagueness and uncertainty. Taking into account these aspects we can provide a more grounded and precise picture of the environment, creating context-aware systems that are more flexible and reliable. It also provides a more accurate inference process, making possible to consider the quality of t...

Context-aware systems must be able to deal with uncertain context information. We propose a generic context architecture and representation that incorporates the uncertainty of context elements in terms of upper and lower bounds of probabilities. It is shown how opinion nets can be used to reason with these upper and lower bound probabilities. In this way it is possible to combine ambiguous or ...