Managing Multiple Spaces Alan Dix, Adrian Friday Lancaster University alan@hcibook.com, adrian@comp.lancs.ac.uk Boriana Koleva, Tom Rodden Nottingham University bnk@cs.nott.ac.uk, tom@cs.nott.ac.uk Henk Muller, Cliff Randell Bristol University henkm@cs.bris.ac.uk, cliff@cs.bris.ac.uk Anthony Steed University College London a.steed@cs.ucl.ac.uk 1. Setting the scene This paper is about our experiences of space in the Equator project (www.equator.ac.uk), in particular, the way in which multiple spaces, both virtual and physical, can co-exist. By this we mean that people and objects may have locations in and relationships to both physical space and one or more virtual spaces, and that these different spaces together interact to give an overall system behaviour and user experience. The concepts we develop in this chapter are driven partly by practical experience, and partly by previous theoretical work such as the models and taxonomies of spatial context in (Dix et al., 2000), the models for mixed reality boundaries (Koleva et al., 1999) and capturing human spatial understanding exposed in sources such maps, myths and mathematics (Dix, 2000). We are also building on established work on informal reasoning about space from the AI and GIS communities (Grigni et al, 1995; Papadias et al., 1996) similar to Allen’s well known temporal relations (Allen, 1991). We start by looking at some of the practical experiences in a number of Equator ‘experience’ projects and how these have each required several kinds of interacting spaces: real and virtual. We then use this as a means to look more abstractly at different kinds of space and the way these overlap and relate to one another. In order to examine some aspects in greater detail we will use two artificial scenarios which each highlight specific problems and issues. Finally, we will discuss how this is contributing to ongoing work including the construction of an Equator ‘space infrastructure’. 2. Spaces we have known Equator is a large multi-site multi-disciplinary project focused on the integration of digital and physical interaction. One of the key methods used in Equator are ‘experience projects’. These experiences are focused around the creation of a particular event or outcome, which allow the integration of practical and theoretical work of many kinds. As the focus of Equator as a whole is the confluence of physical and digital life, unsurprisingly the nature of space has been important in many of these sub-projects. We will discuss four of these here: City, CityWide, the Drift Table and Ambient Wood. In each we will see multiple physical and virtual spaces interacting. 2.1 City The City project allows participants who may be present in person, through virtual reality (VR) or through a simple web interface to all ‘share’ a visit to the Mackintosh Room at the Lighthouse in Glasgow (Brown et al., 2003). The physical visitor walks around the actual