ABSTRACT
Measurement has been defined as the correlation with numbers of entities which are not numbers. As practiced in the developed sciences this is a sufficiently comprehensive, though cryptic, statement of the object of measurement. The problems of measurement merge, at one end, with the problems of predication. In arts like cookery, measurement is not primarily numerical, and the operations used are very often controlled by disciplined judgments on the qualitative alterations of the subject matter. The "real" shape of the penny is round, because from the point of view from which the penny is round, measurements and correlations of other shapes can be carried on most easily. When a laboratory experiment is studied behavioristically, the measurements performed consist in the observation of the movement of a pointer on a scale, or of the superposition of lengths.
