We explore how computer games can be designed to maintain some of the social aspects of traditional game play, by moving computational game elements into the physical world. We have constructed a mobile multiplayer game, Pirates!, to illustrate how wireless and proximity-sensing technology can be integrated in the design of new game experiences. We describe Pirates! and its implementation, and report insights gained during a demonstration at a scientific conference. Observations of test users indicate that Pirates! can be deployed in a social setting where co-located people play together in order to promote social interaction between players and non-players alike.

Collaborative interactions with many existing digital tabletop systems lack the fluidity of collaborating around a table using traditional media. This paper presents a critical analysis of the current state-of-the-art in digital tabletop systems research, targeted at discovering how user requirements for collaboration are currently being met and uncovering areas requiring further development. By considering research on tabletop displays, collaboration, and communication, several design guidelines for effective colocated collaboration around a tabletop display emerged. These guidelines suggest that technology must support: (1) natural interpersonal interaction, (2) transitions between activities, (3) transitions between personal and group work, (4) transitions between tabletop collaboration and external work, (5) the use of physical objects, (6) accessing shared physical and digital objects, (7) flexible user arrangements, and (8) simultaneous user interactions. The critical analysis also revealed several important directions for future research, including: standardization of methods to evaluate co-located collaboration; comparative studies to determine the impact of existing system configurations on collaboration; and creation of a taxonomy of collaborative tasks to help determine which tasks and activities are suitable for tabletop collaboration.

An Exertion Interface is an interface that deliberately requires intense physical effort. Exertion Interfaces have applications in ”Sports over a Distance”, potentially capitalizing on the power of traditional physical sports in supporting social bonding. We designed, developed, and evaluated an Exertion Interface that allows people who are miles apart to play a physically exhausting ball game together. Players interact through a life-size videoconference screen using a regular soccer ball as an input device. The Exertion Interface users said that they got to know the other player better, had more fun, became better friends, and were happier with the transmitted audio and video quality, in comparison to those who played the same game using a non-exertion keyboard interface. These results suggest that an Exertion Interface, as compared to a traditional interface, offers increased opportunities for connecting people socially, especially when they have never met before. Keywords Exertion interface, physical interface, sports interface, social bonding, computer mediated communication, interpersonal trust, funology, sport, video-conferencing

In this paper we present a novel hardware and software platform (STARS) to realize computer augmented tabletop games that unify the strengths of traditional board games and computer games. STARS game applications preserve the social situation of traditional board games and provide a tangible interface with physical playing pieces to facilitate natural interaction. The virtual game components offer exciting new opportunities for game design and provide richer gaming experiences impossible to realize with traditional media. This paper describes STARS in terms of the hardware setup and the software platform used to develop and play STARS games. The interaction design within STARS is discussed and sample games are presented with regard to their contributions to enhancing user experience. Finally, realworld experiences with the platform are reported. Key words: Gaming, tabletop games, tangible interfaces. 1

We describe two games in which online participants collaborated with mobile participants on the city streets. In the first, the players were online and professional performers were on the streets. The second reversed this relationship. Analysis of these experiences yields new insights into the nature of context. We show how context is more socially than technically constructed. We show how players exploited (and resolved conflicts between) multiple indications of context including GPS, GPS error, audio talk, ambient audio, timing, local knowledge and trust. We recommend not overly relying on GPS, extensively using audio, and extending interfaces to represent GPS error.

This paper describes two interface prototypes which we have developed on our augmented desk interface system, EnhancedDesk. The first application is Interactive Textbook, which is aimed at providing an effective learning environment. When a student opens a page which describes experiments or simulations, Interactive Textbook automatically retrieves digital contents from its database and projects them onto the desk. Interactive Textbook also allows the student hands-on ability to interact with the digital contents. The second application is the Interactive Venn Diagram, which is aimed at supporting effective information retrieval. Instead of keywords, the system uses real objects such as books or CDs as keys for retrieval. The system projects a circle around each book; data corresponding the book are then retrieved and projected inside the circle. By moving two or more circles so that the circles intersect each other, the user can compose a Venn diagram interactively on the desk. We also describe the new technologies introduced in EnhancedDesk which enable us to implement these applications.

In this paper, means of enriching computer entertainment experiences by emphasizing physical and social game elements are discussed. A conceptual framework in which the relations between the virtual, the physical, and the social domains are modelled is presented. Interfaces that mediate between the domains are discussed along with a complementary software architecture that helps developing hybrid computer games. Finally, sample games that follow the approach of physical and social augmentation are presented.

We report from a Research Atelier that explored how ubiquitous computing could be applied to fun and entertainment. The Atelier lasted for five days, starting with two days of scenario development and brainstorming activities. This led to three fairly concrete -- though very different -- game ideas. The background and motivation for the Atelier is described, as well as the method used and the games developed.

Ubiquitous computing is a challenging area that allows us to further our understanding and techniques of context-aware and adaptive systems. Among the challenges is the general problem of capturing the larger context in interaction from the perspective of user modeling and humancomputer interaction (HCI). The imperative to address this issue is great considering the emergence of ubiquitous and mobile computing environments. This paper provides an account of our addressing the specific problem of supporting functionality as well as the experience design issues related to museum visits through user modeling in combination with an audio augmented reality and tangible user interface system. This paper details our deployment and evaluation of ec(h)o – an augmented audio reality system for museums. We explore the possibility of supporting a contextaware adaptive system by linking environment, interaction object and users at an abstract semantic level instead of at the content level. From the user modeling perspective ec(h)o is a knowledgebased recommender system. In this paper we present our findings from user testing and how our approach works well with an audio and tangible user interface within a ubiquitous computing system. We conclude by showing where further research is needed.

This paper discusses the Jam-O-Drum multi-player musical controller and its adaptation into a gaming controller interface known as the Jam-O-Whirl. The Jam-O-World project positioned these two controller devices in a dedicated projection environment that enabled novice players to participate in immersive musical gaming experiences. Players' actions, detected via embedded sensors in an integrated tabletop surface, control game play, real-time computer graphics and musical interaction. Jam-O-World requires physical and social interaction as well as collaboration among players.