A Performing Medium for Working Group Graphics


What kind of measures can be made of vmacs performances, and why would we want to? Measurement of simple parameters of performance     - like cursor position over time, results of selection attempts on visual objects, size of drawline marks made, distance objects were dragged, grouping structures created     - are used in representing and teaching basic manipulation skills (figures jnTrackingand cogAidsAtnShifting). Measurers for more complex parameters are in working prototype stage. As an example, one program replays histories in order to search for occurrences of `drag-grouping'; the idea behind this measure is that simple conceptual groupings of visual objects can be inferred by finding spatial juxaposition relations that the operator preserves during dragging newfootnoPatterns. Measures of drag-grouping use temporal and spatial patternings to discover how people are `thinking about' (in a primitive sense) the visual objects. Another approach to getting at underlying cognitive issues is the spatial parsing described in Section 10.1, which is a tool for looking at static spatial patternings during visual communication. Each of the visual languages analyzed is, in part, a set of rules used by humans for collecting a set of visual elements into conceptual groups     - visual phrases     - for interpretation in that language. And Visual Grammar Notation is a perspicuous way of representating those rules, with each grammar visually displaying the patterns of human spatial arrangement for a well-defined subset of visual communication activity.

One promising avenue for future work lies in examing the explicit creation of grouping structures for manipulation which are easy to measure in vmacs. For example, in figure cogAidsTrilogy-cwe might try to find the relation between the manipulative groupings indicated by the tree networks and conceptual groupings (how people see the images together). Now these two kinds of grouping can't be unrelated (unless the operator is trying to trick us), but nor does it seem likely that the relation is one-to-one. Specifying exactly how they are related will take careful research.

But the measures described above only scratch the surface in examining working group graphics; this phenomenon seems to offer fundamental leverage for measuring cognitive behavior. In comparison with protocols taken from a single individual during a cognitive task, working group graphics is explicit, synoptic and graphic. The text-graphics on the group display are explicit and complete in that the group itself monitors to make sure nothing important is left off the display. And at the same time, there is neither room nor time to put up irrelevant material, so the group itself performs synopsis, distilling the salient points from their own verbalizing. In addition, working group graphics uses rich yet easy to process graphic devices of gross texture (line networks, spatial arrangement and juxaposition, variation in text case) to show semantic connections among smaller text-graphic pieces.

However, the cognitive aspects of the current research are still in the fledgling stage, unable to do much with all this leverage. The display of concept development on vmacs may be so rich yet so easy to measure, but the phenomenon of interest seems just out of reach. During the performance, we can see the text-graphics shifting and measure their coursings precisely, so what does that tell us about the coursing of ideas?

Assuming progress can be made on these problems, then in the future perhaps heuristics about text-graphic patternings during concept development can be discovered which could be used by assistive software modules. Under the guidance of such performance-adiminstrators, the group's text-graphic medium might finally become a `rational external device'. A.R. Luria coined this term to describe a card system he designed to help a brain damaged soldier tell a story. The problem was not unlike one often faced by working groups: when telling a story orally, the patient could either generate the pieces or order them, but he couldn't do both. "Replacement of the defective internal schemes by a system of rational external aids provided a practical means of overcoming the patient's defect ..." [Luria66].