Abstract
While it is usual among psychiatrists to express dissatisfaction with psychiatric classification and its problems it is by no means unusual for their psychological colleagues to advocate factor analysis as an effective technique for resolving such problems. For example, Burt (1954) describes factor analysis as “essentially a statistical device for securing the best available scheme of classification”. Yet the problems and the device tend to remain apart, the former becoming intensified, the latter undergoing continued improvements. Twenty-five years ago T. V. Moore (1930) demonstrated that the application of factor analysis to the study of psychiatric disorders was feasible, and more recent work, especially that of Eysenck (e.g. 1947) has impressively shown its fruitfulness. That some clinicians remain sceptical of the claims made for these techniques is, in part, due to the infrequency with which factorial studies bearing on psychiatry have been pursued far enough for their implications to be tested and the findings integrated with those established by other scientific methods. This deficiency may be attributable to the fact that large scale programme research (Eysenck, 1953) is an almost essential condition, if this is to be achieved.