Designing graphical notations: for paper or tools?

In this posting I continue on the theme of designing tools and notations to support modeling.

On and off I've spent the last eight years thinking about the design of graphical (as opposed to purely textual) notations for use in software development. Until I started to build tools to support these notations, my thinking was unintentionally skewed towards how a notation would be used on paper or a whiteboard. As soon as I began building tools I realized that there's a whole range of facilities for viewing, navigating and manipulating models, available in a tool but not on paper or whiteboard. Perhaps I should have realized this from just using modeling tools, but it seems that something more was required to make it sink in! Anyway, I have also noticed that these facilities can not always be exploited if they are not taken into account when the notation is designed: there is a difference between designing a notation to be used in a tool and one to be used on paper. I have written a short article which lays out the argument in a little more detail, and gives a couple of concrete examples. As always, your feedback is valued.