Introduction

In the 1930s, the British Association for the Advancement of Science installed a number of its members with a most peculiar task: to decide whether or not there was such a thing as measurement in psychology. The commission, consisting of psychologists and physicists (among the latter was Norman Campbell, famous for his philosophical work on measurement), was unable to reach unanimous agreement. However, a majority of its members concluded that measurement in psychology was impossible; Campbell (cited in Narens and Luce, 1986, p. 186), for example, asked ‘why do not psychologists accept the natural and obvious conclusion that subjective measurements (…) cannot be the basis of measurement’. Similarly, Guild (cited in Reese, 1943, p. 6) stated that ‘to insist on calling these other processes [i.e., attempts at psychological measurement] measurement adds nothing to their actual significance, but merely debases the coinage of verbal intercourse. Measurement is not a term with some mysterious inherent meaning, part of which may be overlooked by the physicists and may be in course of discovery by psychologists.’ For this reason, Guild concluded that using the term ‘measurement’ to cover quantitative practices in psychology ‘does not broaden its meaning but destroys it’.