SPECIAL ISSUE ON CSCW .1. HUMAN AND TECHNICAL FACTORS OF DISTRIBUTED GROUP DRAWING TOOLS

Groupware designers are now developing multi-user equivalents of popular paint and draw applications. Their job is not an easy one. First, human factors issues peculiar to group interaction appear that, if ignored, seriously limit the usability of the group tool. Second, implementation is fraught with considerable technical hurdles. This paper describes the human and technical factors that have been met and handled by researchers and implementors of group drawing tools. We emphasize our own experiences building four systems supporting remote real time group interaction: GroupSketch and XGroupSketch, both multi-user sketchpads; GroupDraw, a prototype object-based multi-user drawing package, and GroupKit, a groupware toolkit. On the human factors side, we summarize empirically-derived design principles that we believe are critical to building useful and usable collaborative drawing tools. On the implementation side, we describe our experiences with replicated versus centralized architectures, schemes for participant registration, multiple cursors, network requirements, and the structure of the drawing primitives. A brief survey of other approaches to group drawing is also included.