Thematic Apperceptive Techniques (TAT:) help psychologists understand patients' personality and problems by asking the patients to tell stories about pictures. Scoring manuals for quantitative scoring systems give the rules for what ideas to look for in stories and how to give a score. Our psychometric theories about the validity and reliability of tests are made for tests of ability and self-rating scales of symptoms, traits, or behaviors, and not for stories. Some of the psychometric rules used to evaluate ability tests and self-rating scales should not be used with TATs. Patients' stories provide samples of the patient's social-cognitive processes. Each picture shows a situation. TATs follow principles of representative population sampling of situations. Stories are samples of patients' processing of situations. TATS also follow rules of processes. Processes change when situations change. Therefore, TATs should have new rules for reliability. TAT interpretation does not require norms. Scores from different categortes of situations can be compared to understand the patient's problems. Future research needed is described.