Psychotherapists, who by temperament are likely to be tender-minded, have up to now largely failed to devote “attention to the problems of quantitative assessment” (Sutherland et al., 1967), and have perhaps been too prone to regard the complaints of tough-minded critics as manifestations of unconscious resistance. If, as most therapists do, one retains the conviction that patients are altered by the experience of psychotherapy, it should be possible to demonstrate and measure such alteration. The fact that attempts to measure change are often unconvincing is probably a function of the crudity or irrelevance of many of the measuring instruments used.