The specification, development and evaluation of a VE to allow people with Asperger's Syndrome to practise social interaction is described. A "front-ended" style has been adopted, where the emphasis on user consideration is placed during the early stages of the development life cycle, before any VE programming takes place. A model for user-centred design is presented that shows the involvement of different groups of users and professionals at various stages of design. Design guidelines have been derived from literature reviews and empirical examination of existing VEs. These have then been applied within a highly iterative cycle of low -tech VE specification and review. One VE module has been developed and evaluated with a focus on usability.

We describe the design of tangible interfaces to the KidPad collaborative drawing tool. Our aims are to support the re-enactment of stories to audiences, and integration within real classroom environments. A six-month iterative design process, working with children and teachers in school, has produced the “magic carpet”, an interface that uses pressure mats and video-tracked and barcoded physical props to navigate a story in KidPad. Reflecting on this process, we propose four guidelines for the design of tangible interfaces for the classroom. (1) Use physical size and shysical props to encourage collaboration. (2) Be aware of how different interfaces emphasize different actions. (3) Be aware that superficial changes to the design can produce very different physical interactions. (4) Focus on open low-tech technologies rather than (over) polished products.

Abstract Expert systems are knowledge-based reasoning systems which attempt to capture the expertise and problem-solving abilities of a human expert within a fairly narrow field. Human problem-solving is characterised by the ability to handle unexpected events and to approach problems in a variety of ways, reorganising information and adjusting strategies to suit new situations. Hypertext systems are also knowledge-based systems in which chunks of information are linked together in a non-sequential way thus providing the vehicle for intuitive, non-linear access to information which more closely resembles intelligent human behaviour. From these descriptions it would seem that the integration of these two complementary technologies should lead to more ‘intelligent’ problem-solving and information systems. The aim of such integration being to maximise joint performance and to achieve synergy — an integrated system which is greater than the sum of its parts. Hypertext can be viewed in two ways: as a method of conveying information or as a ‘system glue’ for linking computer systems to each other or to a user. These approaches give rise to very different types of system and three distinct types of hybrid hypertext/expert system are identified. The paper considers whether such hybrid systems can be used to solve some of the problems which are found to occur with expert system interfaces or whether the combination of two technologies compounds one set of problems with another.