Abstract
Ubiquitous computing poses new usability challenges that cut across design and development. We are particularly interested in "spaces" enhanced with sensors, public displays and personal devices. How can prototypes be used to explore the user's mobility and interaction, both explicitly and implicitly, to access services within these environments? Because of the potential cost of development and design failure, the characteristics of such systems must be explored using early versions of the system that could disrupt if used in the target environment. Being able to evaluate these systems early in the process is crucial to their successful development. This paper reports on an effort to develop a framework for the rapid prototyping and analysis of ambient intelligence systems.

Abstract
This paper is concerned with support for the process of usability engineering. The aim is to use formal techniques to provide a systematic approach that is more traceable, and because it is systematic, repeatable. As a result of this systematic process some of the more subjective aspects of the analysis can be removed. The technique explores exhaustively those features of a specific design that fail to satisfy a set of properties. It also analyzes those aspects of the design where it is possible to quantify the cost of use. The method is illustrated using the example of a medical device. While many aspects of the approach and its tool support have already been discussed elsewhere, this paper builds on and contrasts an analysis of the same device provided by a third party and in so doing enhances the IVY tool.

Abstract
Although the take-up of formal approaches to modelling and reasoning about software has been slow, there has been recent interest and facility in the use of automated reasoning techniques such as model checking 151 oil increasingly complex systems. In the case of interactive systems, formal methods can be particularly useful in reasoning about systems that involve complex interactions. These techniques for the analysis of interactive systems typically focus on the device and leave the context of use undocumented. In this paper we look at models that incorporate complexity explicitly, and discuss how they can be used in a formal setting. The paper is concerned particularly with the type of analysis that can be performed with them.

Abstract
In recent years, advances in software tools have made it easier to analyze interactive system specifications, and the range of their possible behaviors. However, the effort involved in producing the specifications of the system is Still Substantial. and a difficulty exists regarding the specification of plausible behaviors on the part of the user. Recent trends in technology towards more mobile and distributed Systems further exacerbates the issue, as contextual factors come in to play, and less structured, more opportunistic behavior on the part of the user makes purely task-based analysis difficult. In this paper we consider a resourced action approach to specification and analysis. In pursuing this approach we have two aims - firstly. to facilitate a resource-based analysis of user activity. allowing resources to be distributed across a number of artifacts, and secondly to consider within the analysis a wider range of plausible and opportunistic user behaviors without a heavy specification overhead, or requiring commitment to detailed user models.

Abstract
The paper explores the role that formal modeling may play in aiding the visualization and implementation of usability requirements of a control panel. We propose that this form of analysis should become a systematic and routine aspect of the development Of Such interfaces. We use a notation for describing the interface that is convenient to use by software engineers, and describe a set of tools designed to make the process systematic and exhaustive.

Abstract