I’ll give you an example of something that I put into Mathematica that I thought was a good idea but that turned out not to be. It was this function called Short. It just has to do with printing our expressions…

It goes through the expression [as] a tree and it has a certain amount of energy that starts off at the top of the tree, and it allocates the energy in different ways as it goes down the branches of the tree. It does a fairly nice job of showing you the structure of the expression with some little ellipses. As I say, it seemed like a good idea. The only catch is, nobody uses it. I haven’t used it in eons. Why do people not use it? I don’t know. But that’s an example of a “Designers Beware”.