It is very difficult to define what is meant by computer-aided design since the complete definition is, in fact, the sum and substance of the total p… - Douglas T. Ross

A general theme for what I'm trying to convey and what actually drove me and my very industrious and creative project members over all these years, is... that there is much more to it than pictures. It has to be a picture language. There has to be meaning there, and the meaning is useful. You're trying to solve problems. So it really comes down to man machine problem solving . Better means of communication and expression is what always has driven our work.

I was sort of a hellraiser with a bunch of friends, most of whom were squeaking by with C's and D's while I was getting an A-average and should have been doing better. I did a lot of things on my own. I liked to make things with my hands. There was a lot of woodworking, model building, and model railroading. I collected stamps, and did various things in chemistry. I used to make things that exploded, and all that sort of thing. So I evidently got quite a good background in science. I always had a knack for that sort of thing. The hospital had a subscription to Scientific American and Science. So things came every week and I consumed them...

(SA) combines blueprint-like graphic language with the nouns and verbs of any other language to provide a hierarchic, top-down, gradual exposition of detail in the form of an SA model. The things and happenings of a subject are expressed in a data decomposition and an activity decomposition, both of which employ the same graphic building block, the SA box, to represent a part of a whole. SA arrows, representing input, output, control, and mechanism, express the relation of each part to the whole.