Visual programming: limits of graphic representation

The effectiveness of graphic representations of computer programs is analyzed. Existing software metrics are modified for use in analyzing diagrams, and two new metrics are proposed: graphic token count and diagram class complexity. A graphic design measure, data density, is transformed into a computer science measure, token density. Using these metrics, graphic representations can be compared to each other and to textual representations. Conclusions are drawn about the relative strengths of graphic and textual representation