Since I wrote my thesis, a number of interesting products have come out - and two successful ones in particular are consistent with my generalizations about what works in the visual realm.
One is a product called Trellix - the compact graph representations are powerful and effective in combination with an intelligent labeling function.
This is the HTML version of Jeffrey Nickerson's Ph.D. thesis entitled Visual Programming.
The text includes many diagrams that have been reduced in resolution to be viewable on the Web. In the paper
version of the thesis, all the diagrams are at 300 dpi minimum resolution. The paper version can be ordered from
University Microfilm Inc. ( UMI Dissertation Express).
UMI offers an ordering service for both libraries and individuals. You will need the thesis number: #9514409.