TITLE: Notations, Representations, and Names AUTHOR: Eugene Wallingford DATE: June 18, 2019 3:09 PM DESC: ----- BODY: In The Power of Simple Representations, Keith Devlin takes on a quote attributed to the mathematician Gauss: "What we need are notions, not notations."
While most mathematicians would agree that Gauss was correct in pointing out that concepts, not symbol manipulation, are at the heart of mathematics, his words do have to be properly interpreted. While a notation does not matter, a representation can make a huge difference.
Spot on. Devlin's opening made me think of that short video of Richard Feynman that everyone always shares, on the difference between knowing the name of something and knowing something. I've seen people mis-interpret Feynman's words in both directions. The people who share this video sometimes seem to imply that names don't matter. Others dismiss the idea as nonsense: how can you not know the names of things and claim to know anything? Devlin's distinction makes clear the sense in which Feynman is right. Names are like notations. The specific names we use don't really matter and could be changed, if we all agreed. But the "if we all agreed" part is crucial. Names do matter as a part of a larger model, a representation of the world that relates different ideas. Names are an index into the model. We need to know them so that we can speak with others, read their literature, and learn from them. This brings to mind an article with a specific example of the importance of using the correct name: Through the Looking Glass, or ... This is the Red Pill, by Ben Hunt at Epsilon Theory:
I'm a big believer in calling things by their proper names. Why? Because if you make the mistake of conflating instability with volatility, and then you try to hedge your portfolio today with volatility "protection" ...., you are throwing your money away.
Calling a problem by the wrong name might lead you to the wrong remedy. Feynman isn't telling us that names don't matter. He's telling us that knowing only names isn't valuable. Names are not useful outside the web of knowledge in which they mean something. As long as we interpret his words properly, they teach us something useful. -----