Now the background. Henry and I have quite a lot of history in common.
We both came to math education as mathematician-modelers, Henry from a distinguished position at Bell Labs and me as a theoretical physicist.
We were early explorers of teaching modeling.
I taught my first modeling course in 1963. Of course, like Monsieur Jourdain in the Molière play who was surprised to discover he’d been speaking prose all his life, most people have always done some modeling—but to be aware of it and to talk about teaching it is something else.
And, well, Henry and I have been doing that ever since—fifty years of modeling, with some real progress but an awful lot still to do until it becomes a way of thinking for everybody.