Members of a designing group might communicate easily by using a common display such as a blackboard or a large sheet of paper. These media contain elements of graphics and text, which must be drawn and manipulated by one or more operators. In the first part of this research paper, the author uses a stepwise approach to discuss the features required of an efficient performing medium for working group graphics. He briefly describes three examples of non-computer media (although his third example, “manipulable card paper graphics,” is unclear) and gives a systematic list of the required features.

In the second part of the paper, Lakin presents vmacs, a computer medium for working group graphics that is a powerful graphics editor (vmacs is the author’s trademark). He shows how vmacs works and evaluates its performance based on generality, speed, quality, and dynamics.

The reader or even the user will find very interesting ideas in this paper. The text is short but clear. Some of the figures are too small, though, and the hand sketches are too crude.