People do a lot of their work without computers, or using different tools on different computer systems, and have developed their own work practices for these situations. Even in a heavily computerized individual workplace, users often work both with computers and on the physical desktop. Neither one can replace the other. For example, printed materials such as books and magazines are still an indispensable source of information.

Therefore, when designing realtime shared workspaces, depending on the task and the media of the information to be shared (paper or computer file), co-workers should be able to choose either computers or desktops, and to switch between them freely. One person's choice should be independent of the other members' choices. Group members should be able to use a variety of heterogeneous tools (computer-based and manual tools) in the shared workspace simultaneously. To realize such a seamless shared workspace, we designed TeamWorkStation-1 (TWS-1).




The key design idea of TWS-1 is a "translucent overlay" of individual workspace images. TWS-1 combines two or more translucent live-video images of computer screens or physical desktop surfaces using a video synthesis technique. Translucent overlay allows users to combine individual workspaces and to point to and draw on the overlaid images simultaneously. We chose video as the basic medium of TWS because it is the most powerful for fusing presentations of a variety of traditionally incompatible visual media such as papers and digital documents.




Since TWS-1 was designed for laboratory experiments to verify the concept of seamless shared workspaces, we did not pay much attention to the number of cables or the communication bandwidth. As a result, the system configuration became complex and difficult to maintain. This complexity prevented us from conducting the field tests using publicly available digital networks, and motivated us to start designing a completely new system, TeamWorkStation-2 (TWS-2).

TeamWorkStation-2 (TWS-2) was designed to provide a shared workspace over narrowband ISDN (N-ISDN) Basic Rate Interface (2B+D) and the Primary Rate Interface (H1/D) using the CCITT H.261 standard of moving picture transmission. We chose N-ISDN, especially Basic Rate Interface as the target network because of its wide spread availability in Japan .

For more information about this project, please refer the following papers and video.

Papers on TeamWorkStation-1 and 2

Ishii, H., Kobayashi, M. and Arita, K., "Iterative Design of Seamless Collaboration Media," Communications of the ACM (CACM), Special Issue on Internet Technology, ACM, Vol. 37, No. 8, August 1994, pp. 83-97.

Ishii, H., Arita, K., and Yagi, T., "Beyond Videophones: TeamWorkStation-2 for Narrowband ISDN," Proceedings of Third European Conference on Computer-Supported Cooperative Work (ECSCW '93), Kluwer Academic Publishers, Dordrecht, Netherlands, September 1993, pp. 325-340.

Ishii, H., "Translucent Multiuser Interface for Realtime Collaboration," IEICE Transactions on Fundamentals of Electronics, Communications and Computer Science, Special Issue on Next Generation Human Interface, Institute of Electronics, Information and Communication Engineers of Japan (IEICE), Vol. E75-A, No. 2, February 1992, pp. 122-131.

Ishii, H., and Miyake, N., "Toward An Open Shared Workspace: Computer and Video Fusion Approach of TeamWorkStation," Communications of the ACM (CACM), Special Issue on CSCW, ACM, Vol. 34 No. 12, December 1991, pp. 37-50.

Ishii, H. and Arita, K., "ClearFace: Translucent Multiuser Interface for TeamWorkStation," Proceedings of Second European Conference on Computer-Supported Cooperative Work (ECSCW '91), Amsterdam, 25-27 September 1991, pp. 163-174.

Ishii, H., "TeamWorkStation: Towards a Seamless Shared Workspace," Proceedings of Conference on Computer-Supported Cooperative Work (CSCW '90), ACM SIGCHI and SIGOIS, Los Angeles, 7-10 October 1990, pp. 13-26.

Ishii, H. and Ohkubo, M., "Design of TeamWorkStation: A Realtime Shared Workspace fusing Desktops and Computer Screens," Proceedings of Conference on Multi-User Interfaces and Applications, Ed. S. Gibbs, North-Holland, IFIP WG8.4, Crete, Greece, 24-26 September 1990, pp. 131-142.

Videos on TeamWorkStation-1 and 2

Ishii, H., Arita, K., and Kobayashi, M., "Toward Seamless Collaboration Media: From TeamWorkStation to ClearBoard," SIGGRAPH Video Review, CSCW '92 Technical Video Program, Issue 87, Item 6, ACM, New York, 1992.

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