Modelling Interactive Experience, Function and Performance in Ubiquitous Systems

Abstract The cost of deploying a ubiquitous system to enhance a physical environment is likely to be considerable. The success of its deployment is highly dependent on its context: the physical environment and the activities that are to be carried out within it. This paper provides an initial exploration of whether stochastic process algebras (in particular PEPA with a Fluid Flow semantics) might be used to explore consequences before deployment. The focus of the exploration is to aid understanding of how a proposed system supports users within the environment. The challenge is to provide notations and techniques that will enable the analysis of potentially complex systems

User-centred design of flexible hypermedia for a mobile guide: Reflections on the hyperaudio experience

A user-centred design approach involves end-users from the very beginning. Considering users at the early stages compels designers to think in terms of utility and usability and helps develop the system on what is actually needed. This paper discusses the case of HyperAudio, a context-sensitive adaptive and mobile guide to museums developed in the late 90s. User requirements were collected via a survey to understand visitors’ profiles and visit styles in Natural Science museums. The knowledge acquired supported the specification of system requirements, helping defining user model, data structure and adaptive behaviour of the system. User requirements guided the design decisions on what could be implemented by using simple adaptable triggers and what instead needed more sophisticated adaptive techniques, a fundamental choice when all the computation must be done on a PDA. Graphical and interactive environments for developing and testing complex adaptive systems are discussed as a further step towards an iterative design that considers the user interaction a central point. The paper discusses how such an environment allows designers and developers to experiment with different system’s behaviours and to widely test it under realistic conditions by simulation of the actual context evolving over time. The understanding gained in HyperAudio is then considered in the perspective of the developments that followed that first experience: our findings seem still valid despite the passed time

Talk your way round: a speech interface to a virtual museum

Purpose: To explore the development of a speech interface to a Virtual World and to consider its relevance for disabled users. Method: The system was developed using mainly software that is available at minimal cost. How well the system functioned was assessed by measuring the number of times a group of users with a range of voices had to repeat commands in order for them to be successfully recognised. During an initial session, these users were asked to use the system with no instruction to see how easy this was. Results: Most of the spoken commands had to be repeated less than twice on average for successful recognition. For a set of ‘teleportation’ commands this figure was higher (2.4), but it was clear why this was so and could easily be rectified. The system was easy to use without instruction. Comments on the system were generally positive. Conclusions: While the system has some limitations, a Virtual World with a reasonably reliable speech interface has been developed almost entirely from software which is available at minimal cost. Improvements and further testing are considered. Such a system would clearly improve access to Virtual Reality technologies for those without the skills or physical ability to use a standard keyboard and mouse. It is an example of both Assistive Technology and Universal Design

Tangible user interfaces : past, present and future directions

In the last two decades, Tangible User Interfaces (TUIs) have emerged as a new interface type that interlinks the digital and physical worlds. Drawing upon users' knowledge and skills of interaction with the real non-digital world, TUIs show a potential to enhance the way in which people interact with and leverage digital information. However, TUI research is still in its infancy and extensive research is required in or- der to fully understand the implications of tangible user interfaces, to develop technologies that further bridge the digital and the physical, and to guide TUI design with empirical knowledge. This paper examines the existing body of work on Tangible User In- terfaces. We start by sketching the history of tangible user interfaces, examining the intellectual origins of this field. We then present TUIs in a broader context, survey application domains, and review frame- works and taxonomies. We also discuss conceptual foundations of TUIs including perspectives from cognitive sciences, phycology, and philoso- phy. Methods and technologies for designing, building, and evaluating TUIs are also addressed. Finally, we discuss the strengths and limita- tions of TUIs and chart directions for future research