Title: Issues and Experiences Designing and Implementing
Two Group Drawing Tools
Authors: Greenberg, S., Roseman, M., Webster, D., and Bohnet, R.
Citation: Proceedings of the Twenty-fifth Annual Hawaii International Conference on the System Sciences, Vol. IV, IEEE Computer Society Press, pp. 139-150.
Reprinted in: Baecker, R.M. Readings in Groupware and Computer-Supported Cooperative Work. Morgan Kaufmann Publishers, San Francisco, 1993, pp. 609-620.
GroupSketch allows an arbitrary number of people to draw on a piece of virtual paper. Features include a WYISIWIS interface, multiple cursors, and instantaneous update of user actions. GroupDraw, is an object-oriented drawing program. Users can create, move, resize and delete objects.
Studies on GroupSketch revealed that: (1) people tend to concentrate intently on the work surface for tele-data and tele-presence, (2) people focus attention on objects by pointing or circling them, (3) people can and will work simultaneously on any part of the display.
Several issues were discussed. The first concerns a replicated versus a centralized architecture. These approaches have their advantages and disadvantages. Both systems use replicated architectures.
A second issue concerns registration. GroupSketch uses a central registrar while GroupDraw uses a distributed registration scheme.
Both systems implemented multiple cursors differently. GroupSketch bypassed standard libraries and manipulated the displays and mouse device drivers directly. However, this was costly in terms of effort and resulted in a bug. In GroupDraw, multiple cursors were implemented using standard interface toolkits.
Finally, a survey of some group drawing tools were given. These were divided into whether they followed Tang's principals ("good") or not ("bad"). The former included VideoDraw and Team WorkStation. The latter included Boardnoter, XSketch and WScrawl.