It is certainly a good ambition to clarify through a glossary how we use words like theory, model, hypothesis, and research question. The authors should be commended for trying. However, I found their views on the building of new theory not convincing.

(1) The whole approach to theory seems somewhat unrealistic. One crucial aspect is missing, in my view. Does theory come from an orderly process, like when we build a house, starting with the foundation, then the load bearing walls, etc? Here, “theory building” is depicted as starting with a framework (where does the framework come from?), then moving to theory that is later tested in a model. It seems to me that the birth of new theory is a much more chaotic process, the characteristics of which we should learn to recognise.

A 100 years ago last year Einstein’s theories about light and relativity were formulated. A visit to the Einstein exhibition in Berlin last summer convinced me that his theories …