Ubiquitous and mobile technologies provide opportunities for designing novel learning experiences that move out of the classroom. Information can be presented and interacted with in a variety of ways while exploring a physical environment. A key issue this raises is when, where, what and how much? Our research is concerned with the design, delivery and interaction of digital information when learning about ecology outdoors. We present a framework of the different forms of digital augmentation and the different processes by which they can be accessed. Using the framework, we designed an outdoors learning experience, aimed at encouraging students to carry out contextualized scientific enquiry and to reflect on their interactions. Pairs of 11-12 year olds explored a woodland and were presented at certain times with different forms of digital augmentation. Our study showed that this kind of exploration promoted interpretation and reflection at a number of levels of abstraction.

In this paper we discuss the use of models of space in the building of mixed-reality systems. By model of space we mean a geometric or symbolic description associated with a physical space. We outline several types of model that exist, how they are surveyed and authored, how they are represented to the users and how they are supported by middleware and sensors. We show that systems often contain numerous models of space and we discuss the issues in maintaining or reifying assumptions about transformations between models. We illustrate these ideas by describing the implementation of a collaborative mixed-reality system that allows users to experience a museum in three modalities: physically colocated visitor with personal digital assistant guide, virtual reality visitor and Web visitor.

Museums attract increasing numbers of online visitors along with their conventional physical visitors. This paper presents a study of a mixed reality system that allows web, virtual reality and physical visitors to share a museum visit together in real time. Our system allows visitors to share their location and orientation, communicate over a voice channel, and jointly navigate around a shared information space. Results from a study of 34 users of the system show that visiting with the system was highly interactive and retained many of the attractions of a traditional shared exhibition visit. Specifically, users could navigate together, collaborate around objects and discuss exhibits. These findings have implications for non-museum settings, in particular how location awareness is a powerful resource for collaboration, and how 'hybrid objects' can support collaboration at-a-distance.