What's the difference between categorical and numerical data?

Almost all surveymonkey type forms wind up collecting a shedload of categorical data which is then pounded with jackhammers into specious numerical form, to theorise about.

Managing categorical data is pretty much about how long you've been playing with it. I can think of a lot of past SQL schema which used typed fields, and our entire working days could be filled by agonising conversations about when to change from a restricted type of categories, to a freeform field.

Dewey and the like has surprising outcomes. The Name of the Rose Models the complexity of Borges Library in 3-space, but everyone knows that there are alternative L-space forms of relationship between works, which defy simple typing.