We propose an approach to creating shared mixed realities based on the construction of transparent boundaries between real and virtual spaces. First, we introduce a taxonomy that classifies current approaches to shared spaces according to the three dimensions of transportation, artificiality, and spatiality. Second, we discuss our experience of staging a poetry performance simultaneously within real and virtual theaters. This demonstrates the complexities involved in establishing social interaction between real and virtual spaces and motivates the development of a systematic approach to mixing realities. Third, we introduce and demonstrate the technique of mixed-reality boundaries as a way of joining real and virtual spaces together in order to address some of these problems.

We review current spatial approaches to CSCW (mediaspaces, spatial video conferencing, collaborative virtual environments and telepresence)and classify them along the proposed dimensions of transportation, artificiality and spatiality.This classification leads us to identify new shared space application so called mixed realities.We present an example of a mixed reality called the Internet Foyer, an application which provides a unified entry point into an organisation's physical and electronic environments and which supports awareness and chance encounters between the occupants of physical and synthetic space.

Abstract We present a virtual reality application called VR‐VIBE which is intended to support the co‐operative browsing and filtering of large document stores. VR‐VIBE extends a visualisation approach proposed in a previous two dimensional system called VIBE into three dimensions, allowing more information to be visualised at one time and supporting more powerful styles of interaction, The essence of VR‐VIBE is that multiple users can explore the results of applying several simultaneous queries to a corpus of documents. By arranging the queries into a spatial framework, the system shows the relative attraction of each document to each query by its spatial position and also shows the absolute relevance of each document to all of the queries. Users may then navigate the space, select individual documents, control the display according to a dynamic relevance threshold and dynamically drag the queries to new positions to see the effect on the document space. Co‐operative browsing is supported by directly embodying users and providing them with the ability to interact over live audio connections and to attach brief textual annotations to individual documents. Finally, we conclude with some initial observations gleaned from our experience of constructing VR‐VIBE and using it in the laboratory setting.