This volume presents the results of a joint National Science Foundation and European Commission Workshop which was set up to identify the future key strategic research directions in the areas of human-centred interaction, online communities and virtual environments. A research agenda is proposed for each area. There is an urgent need to make interaction more centred around human needs and capabilities, and to consider the human environment in virtual environments and in other contextual information-processing activities. The overall goal is to make users more effective in their information or communication tasks by reducing learning times, speeding up performance, lowering error rates, facilitating retention, and increasing subjective satisfaction. Online communities is an area of rapid and dynamic growth with new kinds of interaction, behaviours, communication, and relationship to the world of users and information. Guidelines for basic user interface design need to be extended to accommodate these new technologies and interfaces to users. Fruitful lines of research investigation in all these areas are set out in this book.