The goal of this work is to provide users immersed in a multiplatform environment with the possibility of interacting with an application while freely moving from one device to another. We describe the solution that we have developed for a service to support platform-aware runtime migration for Web applications. This allows users interacting with an application to change device and continue their interaction from the same point. The service performs the migration of the application taking into account its runtime state and adapting the application interface to the features of the target platforms. The service is optimized for applications developed through a model-based, multiple-level approach. The intelligence of the adaptive interfaces resides in the migration server, which adapts data collected at runtime from their original format to the format best fitting the features of the target platform. We also indicate how it is possible to extend this result in order to support partial migration and synergistic access, by which a part of the user interface is kept on one device during runtime and the remaining part is moved to another with different characteristics.

The wide variety of devices currently available, which is bound to increase in the coming years, poses a number of issues for the design cycle of interactive software applications. Model-based approaches can provide useful support in addressing this new challenge. In this paper we present and discuss a method for the design of nomadic applications showing how the use of models can support their design. The aim is to enable each interaction device to support the appropriate tasks users expect to perform and designers to develop the various device-specific application modules in a consistent manner.

This paper aims to provide a discussion of how model-based approaches and related tools have been used to address important issues for obtaining usable interactive software and the new challenges for this research area. The paper provides an analysis of the logical descriptions that can be used in the design of interactive systems and how they can be manipulated in order to obtain useful results. This type of approach has recently raised further interest in the ubiquitous computing field for supporting the design of multi-device interfaces. The new challenges currently considered are mainly in the area of end-user development, ambient intelligence, and multimodal interfaces.

In this paper, we describe a solution to support automatic platform-dependent semantic redesign. This is obtained within the framework of TERESA, a model-based environment supporting flexible development of multi-device interactive applications. The goal is to show how semantic information regarding the interactive part of a Web application can support more flexible and effective solutions for adapting the interface to different platforms.

Faults in the way a system works are often attributed to user error. Formal verification is one approach advocated to help avoid errors. Previous work has concentrated on ensuring that implementations meet specifications or that safety or liveness properties hold of a specification. However, systems verified in this way are still prone to catastrophic user errors. The designs of computer systems can often provoke certain classes of user errors. Indeed such problems are ubiquitous in every-day life. An example is the post-completion error where the user omits some necessary termination action. Work from the fields of cognitive psychology and human computer interaction suggest that such user errors are avoidable if systems are designed appropriately. We demonstrate that, by adopting a user-centric approach to system verification, formal proof methods can both detect and prove the absence of such system design errors. Furthermore, this approach can be integrated with traditional system verification methods. In particular, we show how the HOL proof system can be used to verify the absence of post-completion errors within the framework of a traditional hardware verification.

The increasing availability of new types of interaction devices raises the need for new methods and tools to support the design and development of highly usable context-sensitive nomadic applications accessible through multiple platforms. This paper provides an overview and discusses a solution based on the use of multiple levels of abstractions, which has been studied within the framework of the European project CAMELEON. Moreover it addresses the problem of evaluating the usability of these tools by discussing the specific issues, the criteria and methodologies applied as well as some results obtained in an experimental activity on the subject.

Abstract. Tools based on the use of multiple abstraction levels have shown to be a useful solution for developing multi-device interfaces. To obtain general solutions in this area it is important to provide flexible environments with multiple entry points and support for redesigning existing interfaces for different platforms. In general, a one-shot approach can be too limiting. This paper shows how it is possible to support a flexible development cycle with entry points at various abstraction levels and the ability to change the underlying design at intermediate stages. It also shows how redesign from desktop to mobile platforms can be obtained. Such features have recently been implemented in a new version of the TERESA tool. 1