Whole-Body Interactions For Very Large Wall Displays Garth Shoemaker and Kellogg S. Booth Department of Computer Science University of British Columbia 201-2366 Main Mall Vancouver, B.C. V6T 1Z4 {garths, ksbooth}@cs.ubc.ca ABSTRACT Very large interactive wall displays do not lend themselves to use with traditional interaction modalities such as mice and keyboards. It is necessary that we develop new interaction methods better suited to such systems. We have taken a body- centric approach in developing such techniques, where the body itself is used for input, and an on-screen shadow representation of the body is employed for feedback. We describe completed work focusing on the shadow aspect of the proposed method, as well as currently ongoing work exploring the gestural input aspects. Categories and Subject Descriptors H.5.3 [Information Interfaces And Presentation]: Input devices and strategies. General Terms Human Factors Keywords Interaction techniques, large wall displays, shadows, whole body interaction. 1. INTRODUCTION Computer display hardware technology is advancing at such a pace that in a relatively short time very large wall sized displays (e.g. Figure 1) will be practical and affordable. Unfortunately these advancements in hardware technology have not been matched by equivalent advancements in interaction technology. It is clear that the traditional techniques of mouse and keyboard are not appropriate for such large displays. Mice and keyboards are designed for users who are stationary and sitting at a desk, whereas users of wall displays are often standing and mobile. However, despite a widespread acceptance of the inappropriateness of keyboard and mouse, no alternate model of interaction has emerged as dominant. Several interaction approaches for large displays have been proposed by researchers. One such approach is based on the metaphor of touch and pen input. This is intuitive to users, but is limited in that it only supports point interaction, and also requires users to be within physical reach of the display. In contrast, other proposed approaches, such as laser pointers and mid-air gesture techniques, have the benefit of functioning at a distance from the display. Unfortunately laser pointer techniques provide limited awareness information to collaborators, and many gesture-based techniques are difficult to learn. Based on what is known of how people interact in the physical world with whiteboards, tables, and other tools, we believe that there are several requirements that any interaction technique must fulfill in order to be widely adopted in the long term. First, such a technique must be usable at a distance from the display. Second, the technique must provide rich awareness information to users, collaborators, and observers. Third, such a technique must provide a body-centered interaction experience. The details of each of these requirements are discussed in later sections. This position paper describes ongoing work involving the development of interaction techniques for large wall displays. Early stages of work involved the development of a novel shadow-based interaction technique that supports interaction at a distance, and provides rich awareness information. We are in the process of extending this early in order to evaluate it in realistic scenarios as well as to develop support for richer body-centered interaction. 2. RELATED WORK Many researchers have explored the use of a user's body for interaction with large displays. We discuss that work here. First, highly influential early work by Krueger et al. [4] explored the use of silhouettes for supporting interaction with large displays. This work was exploratory, and focused on interaction for the sake of artistic expression, but nevertheless has served as © Garth Shoemaker and Kellogg S. Booth 2008. Published by the British Computer Society Figure 1. Collaboration around a large display (mockup).