I’ve done a little diagramming using Omni Graffle Pro today, and here are some quick ideas. I’m not a big fan of UML, although I think that diagrams can convey a lot. I feel that UML as a format is too constrained. I know that the standard can’t be too big, though. I just feel that with a free format, you can invent stuff that’s intuitive. Ad hoc. Constructs that are invented to serve that particular purpose.

One thing I thought of was that lines should be curves to be more easily distinguished from the boxes. Also, use color or gray scales to indicate what’s primary and what’s secondary. Also, use different thickness on lines (curves) to indicate things that are more important. For instance, in my diagram that I created today, there’s some 2pt lines that indicate a sequence of messages between objects. Other lines are 1pt and represent calls that take place “on sideroads” from the main sequence (I don’t know if that came out right).

I hade some more things but I can’t think of them right now. Tufte’s ideas can definitely be applied to object diagrams. Micro-macro readings (is that part of UML at all?), “to clarify, add detail”, etc. I wonder what he would say of UML, by the way.