ABSTRACT
The essential requirement for the use of the single case in fundamental research would seem to be that of predictive experimental control. One of the most consistent advocates of the need for the experimental study of the single case has been Dr. M. B. Shapiro of the Institute of Psychiatry of the University of London, who has, in effect, been the principal founder of one British school of experimental-clinical psychology. The main problems the psychologists set for themselves were, first, to obtain some measure of his symptoms, and, second, by some means to gain control over them. Scaling procedure has the incidental effect of helping to ensure that the patient has the same understanding of the questionnaire as the psychologist. If the control subject had not been different from the patient, the notion of a visual-auditory association difficulty as the basis of the patient's reading difficulty would not have been upheld.
