Classifying science and technology: two problems with the UNESCO system

Systems of classifying knowledge are of key importance because they can provide a kind of spatiotemporal ‘snapshot’ of science, of the sphere of ideas, of the culture of a given period. But such snapshots are, inevitably, perishable. In 1966, UNESCO assigned itself the task of developing an international standard system for classifying science and technology.1 In this it eventually succeeded, although it was not until 1988 that the now well known International Standard Nomenclature for Fields of Science and Technology was formally proposed.2 Despite the fact that this nomenclature was initially intended as a system for classification of research papers and doctoral dissertations, nowadays the UNESCO system has become an essential international guide for many organisations and research institutions, which use it for a whole variety of purposes, for example for definition of research guidelines, cataloguing thematic projects, advertising research positions with public bodies, categorising scientists for subsequent scientific evaluations, and so on.