2. FEATURES OF TEXT-GRAPHIC MANIPULATION FOR WORKING GROUPS

This Section strives for a delicate balance, attempting to characterize the phenomenon of text-graphic manipulation which lies `behind' the examples while at the same time aware that our view is admittedly constrained by their limited technology. Yet the examples are also liberating in their own way, demanding capabilites not easily attained on computer graphics systems. What is ultimately at stake is supporting the `heir' to blackboard activity. We want to include all the features of text-graphic manipulation found in earlier instances of that activity without being restrained to them.

2.1 Chronological       If we were to come upon a text-graphic performance cold and unprepared, what might strike us first is that it is a dynamic phenomenon, unfolding over time: something's moving. What's moving is the text-graphics, described below. The state of the text-graphics at any one time can be captured in a static image or frame. Yet the performance as a whole cannot be captured in any one frame, but instead must be represented as a dynamic sequencing of the frames over time.

2.2 Text-Graphic       The fact that text-graphic manipulation unfolds over time allows us to observe how objects precipitate out of the activity (why chronology was introduced first). That is, a flurry of activity is observed and then there is a pause     - the difference in the image state before and after the flurry is a new object (or a manipulation of an old object). Sometimes new objects are text, sometimes graphics, sometimes both.

Static frames from the examples show the kind of images that are being manipulated: text and graphics in spatial arrangement. As a general policy, we don't want to say whether any particular object is text or graphics until we need to. Oft times the distinction between text and graphics is dubious at best     - perhaps the group will be using Chinese characters or circuit diagram symbology.

2.3 Manipulatory       Now that in the course of describing this phenomenon we have time, and text-graphics, then just an eye-blink later we have manipulation. It's thanks to manipulation that the text-graphics change over time (and in changing, we can see what the pieces of text-graphics it are). Manipulation includes generating, moving, modifying and erasing text-graphic objects. We observe that sometimes operators want to manipulate just little pieces, whereas othertimes they want to manipulate groups of objects as a unit (most apparent in the manipulable cards).

2.4 Performed       Working group graphics is performed by an operator for a group. This fact helps characterize the operation of the medium, and the nature of the medium being operated. There is a performer, and there are consumers of the performance. The consumers are there to watch the images, using them as explicit group memory. The display can be easily seen by all members of the group.

2.5 Fast       What is fast? It is manipulation of text-graphic objects in time. In working group graphics, the agility of text-graphic manipulation is paramount. Leisurely illustration will not do     - the group will get bored or lose their train of thought. Loss of a minute may mean loss of an idea. Figure 4 is the final frame from the large sheet paper graphics performance in figure 2; it took the operator 20 minutes to make this image. Figure 5 shows generation times for selected images in figure 4 as timed from the video tape of the performance. The images are being put up there very quickly. In addition to initial image generation, agile manipulation of images observed in the examples includes erasibility (blackboard) and shuffling (manipulable cards).

Figure 4. Final frame in large sheet paper graphics performance depicted in figure 2.

Figure 5. Generation times for subimages from figure 4.

2.6 Unstructured       The media in the three examples do not restrict the kind of objects that can be written or drawn ⁴; nor do they restrict the temporal order in which images are created. The point is, any kind of image can be created     - from diagrams to paragraphs to LISP code to cartoons to matrices     - regulated only by the purpose and style of the operator.

2.7 Structured       Both spatial and temporal structures can be observed in the text-graphic manipulation found in the examples. A formal spatial schema called `mechanical drawing,' for instance, is during the blackboard activity in example one. Mechanical drawing is a system which limits the kind of text-graphics one may create and their arrangement; in fact it could be called a kind of visual language.

Likewise, temporal patterns can be observed in the examples. In the case of the manipulable cards several temporal trends became obvious during the 90 minute performance. Cards were put up on the display space in the upper-middle area first. As more cards appeared, columns began to form. 30 minutes into the session, colored overlays appeared on top of some of the cards. Then at 45 minutes, the line networks showed up. During the course of the performance, 106 cards were generated; as many as 88 were on the display at one time but only 73 were present in the final frame.

2.8 Reflective       Text-graphic manipulation for working groups can be reflective: that is, using a piece of text-graphics which refers to some aspect of a text-graphic performance. The engineers in example one are taking an instant photograph of the final frame on the blackboard (figure 1). Each member of the group in example two was provided with an image of the final frame (figure 4). And the performers in example three made competing plans for the reorganization of the display as part of their performance (figure 6). The plans were themselves pieces of text-graphics each of which diagrammed a possible way to reorganize the display (as it turned out, the final development of the display was guided by a merger of two plans, the one in the lower left and the one in the upper right of figure 6).

The reflecting on performances characteristic of working group graphics can take place both during the act and afterwards. Reflection serves a variety of purposes. During the act, it can be used to guide the performing. And after the fact, reflecting at leisure has more academic uses. Medium designers might want to delineate the manipulation capabilities of equipment. Psychologists might want to study that aspect of the cognitive behavior of the group explicitly displayed in the sequence of image manipulations. And members of a working group want a record of conclusions reached and how they came about.

Reflection manifests itself in two concrete features of text-graphic manipulation. The first is simply the storage and retrieval of static images and image dynamics from performances. The second feature is measurement (one way academics like to reflect on performing). Measurement is embodied in `soft' instruments for uncovering and delineating temporal/spatial patterns in performances. For instance, a more detailed account of the card movements in example three could easily be represented in a table or a chart. In fact, in a sense measurement itself can be described as a kind of text-graphic manipulation: measurement is a transformation on a performance into a text-graphic object in some formal visual language (designed to perspicuously present some structures in the performance and leave out others).