Abstract. Activity theory is based on the concept of tools mediating between subjects and objects. In this theory, an individual’s creative interaction with his or her surroundings can result in the production of tools. When an individual’s mental processes are exteriorized in the form of tools – termed objectification – they become more accessible to other people and are therefore useful for social interaction. This paper shows how our understanding of activity theory has shaped our design philosophy for groupware and how we have applied it. Our design philosophy and practice is exemplified by a description of the BUILD-IT system. This is an Augmented Reality system we developed to enhance group work; it is a kind of graspable groupware which supports cooperative planning. The system allows a group of people, co-located around a table, to interact, by means of physical bricks, with models in a virtual three-dimensional (3D) setting. Guided by task analysis, a set of specific tools for different 3D planning and configuration tasks was implemented as part of this system. We investigate both physical and virtual tools. These tools allow users to adjust model height, viewpoint, and scale of the virtual setting. Finally, our design practice is summarized in a set of design guidelines. Based on these guidelines, we reflect on our own design practice and the

BUILD-IT is a planning tool based on intuitive computer vision technology, supporting complex planning and configuration tasks. It allows a group of people, seated around a table, to move virtual objects with a real brick as interaction handler. With this tool, object manipulation and image display take place within the very same working area. Hence new aspects of interaction and direct response have been added to the computer-based planning process. Together with the image displayed on the table, a perspective view of the situation is projected on a vertical screen. This system offers all kinds of users access to state-of-the-art computing and visualisation, requiring little computer literacy. It offers a new way of interaction, facilitating team-based evaluation of alternative layouts. A connection to the simulation package SIMPLE++ has been realised. Hence, each alternative can be simulated and displayed using the visualisation capabilities of BUILD-IT. M.Fjeld, F. Jourdan, M. Bich...

. BUILD-IT is a planning tool based on computer vision technology, supporting complex planning and composition tasks. A group of people, seated around a table, interact with objects in a virtual scene using real bricks. A plan view of the scene is projected onto the table, where object manipulation takes place. A perspective view is projected on the wall. The views are set by virtual cameras, having spatial attributes like shift, rotation and zoom. However, planar interaction with bricks provides only position and rotation information. Object height control is equally constrained by planar interaction. The aim of this paper is to suggest methods and tools bridging the gap between planar interaction and three-dimensional control. To control camera attributes, active objects, with intelligent behaviour are introduced. To control object height, several real and virtual tools are suggested. Some of the solutions are based on metaphors, like window, sliding-ruler and floor. 1 I...

BUILD-IT is a planning tool based on intuitive computer vision technology, supporting complex planning and configuration tasks. Based on real, tangible bricks as an interaction medium, it represents a new approach to Human Computer Interaction (HCI). It allows a group of people, seated around a table, to move virtual objects using a real brick as a interaction handler. Object manipulation and image display take place within the very same interaction space. Together with the image displayed on the table, a perspective view of the situation is projected on a vertical screen. The system offers all kinds of users access to state-of-the-art computing and visualisation, requiring little computer literacy. It offers a new way of interaction, facilitating team-based evaluation of alternative layouts. Keywords Direct interaction, graspable interface, computer vision, augmented reality M. Fjeld, M. Bichsel & M. Rauterberg (in press): BUILD-IT: a brick-based tool for direct interaction. In D....

GeoTUI is a system designed for geophysicists that provides props as tangible user interface on a tabletop vision-projection system for the selection of cutting planes on a geographical map of a subsoil model. Our GeoTUI system allows the geophysicists to manipulate in the same action and perception space since the movement of the physical artifacts is done on the tabletop and thus constrained to two dimensions. Consequently, it combines the advantages of the spontaneous conditions of user interaction that the geophysicists are commonly used to in their classical paper/pen/ruler environment with the advantages of the use of powerful geological simulation software. We conducted an extensive user study in the workplace of the geophysicists that clearly revealed that using a tangible interaction performs better than using the standard mouse/keyboard GUI for the cutting line selection task on a geographical subsoil map. Consequently, it increases the efficiency for the real-world trade task of hypothesis validation on a subsoil model. Moreover, this geological user case is complex enough to confirm the hypothesis that in space-multiplex conditions, specialized devices perform better than generic ones. Author Keywords TUI; two-handed interaction, tabletop, user study,

BUILD-IT is an up-and-running system putting at work highly intuitive, videobased interaction technology to support complex planning and configuration tasks. It makes state-of-the-art computing and visualisation available to all kinds of users, without requiring any special computer literacy. Based on real, tangible bricks as M. Fjeld, K. Lauche, S. Dierssen, M. Bichsel & M. Rauterberg (1998): BUILD-IT: A Brick-based integral Solution Supporting Multidisciplinary Design Tasks. In A. Sutcliffe, J. Ziegler & P. Johnson (eds.) Designing Effective and Usable Multimedia Systems, pp. 122-133. Boston: Kluwer Academic Publishers. 132 interaction handler, BUILD-IT represents a novelty to Human-Computer Interaction. With this tool, object manipulation and image display take place within the very same working area. Hence, new dimensions of prehension and direct response have been added to Human-Computer Interaction. Technology has a backstage position, whereas creativity and human communicat...

BUILD-IT is a planning tool based on computer vision technology, supporting complex planning and composition tasks. It allows a group of people, seated around a table, to interact with objects in a virtual scene using real bricks. A plan view of the scene is projected onto the table, where object manipulation takes place. Hence, manipulation and display are coincident. A perspective view is projected on the wall, controlled by a brick acting on a virtual camera. The camera requires control of position, pan, tilt, zoom and roll attributes. However, planar interaction with bricks provides only position and rotation information. The topic of this paper is how to bridge the gap between planar interaction and three dimensional (3D) camera control. This is done by introducing additional, active objects whose positional relation to the camera controls the above attributes. KEYWORDS Graspable interaction, camera control, augmented reality INTRODUCTION FIGURE 1: BUILD-IT offers a plan view fo...

We demonstrate basic 2D and 3D interactions in both a Virtual Reality (VR) system, called the Personal Space Station, and an Augmented Reality (AR) system, called the Visual Interaction Platform. Since both platforms use identical (optical) tracking hardware and software, and can run identical applications, users can experience the effect of the way the systems present their information to the end user (as VR or AR). Since the systems use state-of-the-art tracking technology, the users can also experience the opportunities and limitations offered by such technology at first hand. Such hands-on experience is expected to enrich the discussion on the role that VR and AR systems (with optical tracking) could and/or should play within Ambient Intelligence.

Many work environments can benefit from integrated computing devices to provide information to users, record users' actions, and prompt users about the next steps to take in a procedure. We focus on the cell biology laboratory, where previous work on the Labscape project has provided a framework to organize experiment plans and store data. Currently developed

Physical interfaces have been proposed as a way to realize natural interactions with ubiquitous computing environments. The successful design of such interfaces requires design approaches that integrate aspects of our world which are usually treated separately in traditional system development approaches.