The design ideal of the invisible computer, prevalent in the vision of ambient intelligence (AmI), has led to a number of interaction challenges. The complex nature of AmI environments together with limited feedback and insufficient means to override the system can result in users who feel frustrated and out of control. In this paper, we explore the potential of visualizing the system state to improve user understanding. We use projectors to overlay the environment with a graphical representation that connects sensors and devices with the actions they trigger and the effects those actions produce. We also provided users with a simple voice-controlled command to cancel the last action. A small first-use study suggested that our technique could indeed improve understanding and support users in forming a reliable mental model.

Users often find it hard to understand and control the behavior of a Ubicomp system. This gives rise to usability problems and can lead to loss of user trust, which may hamper the acceptance of these systems. We are extending an existing Ubicomp framework to allow users to pose why and why not questions about its behavior. Initial experiments suggest that these questions are easy to use and could help users in understanding how Ubicomp systems work.

Since a growing number of different mobile computing devices are used in pervasive and ubiquitous environments, the need to adopt new approaches for designing and implementing pervasive interactive software with minor effort is emerging. In this paper we present a process that facilitates the design of next-generation interactive software for pervasive environments. We created a distributed runtime infrastructure that enables the distribution of software components on heterogeneous, networked and embedded hardware systems. Some of these components or compositions of components will require interaction by human users from a large range of different devices. To make the deployment of consistent and functional User Interfaces in these pervasive environments easier, Interaction Components are introduced into the runtime infrastructure which enable the presentation of component and service behavior to human users.