All models are wrong, but some are useful

Wrong WayPretty much all models in physics are wrong of course. From Hooke’s model of the force of a spring, to Schrödinger’s equation in quantum mechanics, to Newton’s law for the force of gravity — all are wrong. Or more precisely, are approximations that work for many circumstances but fail in others. I am following in the illustrious footsteps of Hooke, Newton and Schrödinger by developing a model which will be (sometimes) wrong.

I am currently wondering whether I am brave enough to include the quote up top of the post. I have known about it for years, and really liked it. I think it is short, snappy, and makes an important point. Newton’s law of gravity can fail, and then you need to bring out the big gun of relativity, but in many cases Newton’s law is an excellent approximation, and much easier and quicker to work with than the full relativity equation.

But for the paper I am drafting I needed the source of the quote. I didn’t know it, so I looked it up. It is by George Box. I confess I had never heard of him. He was a British born (in 1920) statistician who went on to work in the USA, and only died very recently. There is an autobiographical potted outline of his life in stats here.

The way he describes how he got into statistics is wonderful. He was partway through a degree in chemistry when the second world war broke out, and he was pressed into service doing experiments. Then

“There were a lot of experiments with small animals, I was a lab assistant making biochemical determinations, my boss was a professor of physiology dressed up as a colonel, and I was dressed up as a staff sergeant.

The results I was getting were very variable and I told my colonel that what we really needed was a statistician.

He said “we can’t get one, what do you know about it?” I said “Nothing, I once tried to read a book about it by someone called R. A. Fisher but I didn’t understand it”. He said “You’ve read the book so you better do it”, so I said, “Yes sir”.”

Then we went on to be a leading statistician, working in Princeton and founding the stats department at the University of Wisconsin. He also married R.A. Fisher’s daughter. Amazing.