It has often been suggested that terms are not prone to variation. Moreover, many standardizing organizations and terminology textbooks take a prescriptive approach to term formation and use in which they disparage variation. However, the author believes that variation is not due to arbitrariness or carelessness, but rather that it is well-motivated and useful in expert discourse. The author hypothesizes that multidimensional classification is one of the determining factors behind term choice and she presents an empirical study of the influence of multidimensional classification on term use in which she examines variant terms in context in a one-million word corpus in the specialized subject field of optical scanning technology.