PSYCHIATRY AND PSYCHOLOGY TRADITIONALLY VIEW SEXUAL DEVIATES AS A HETEROGENEOUS MASS OF INDIVIDUALS WHO CAN BE SUBGROUPED ON THE BASIS OF SIMILAR DEVIANT AROUSAL PATTERNS. BUT RELIANCE ON THE SINGLE CRITERION OF DEVIANT AROUSAL IS INSUFFICIENT IN EVALUATING ANY ONE CLIENT, SINCE OTHER COMPONENTS OF THE CLIENT'S SEXUAL BEING ARE SIGNIFICANT. DETAILED AND SPECIFIC EVALUATIONS MUST INCLUDE ASSESSMENT OF DEVIANT AROUSAL, HETEROSEXUAL AROUSAL, HETEROSOCIAL SKILLS, AND GENDER ROLE BEHAVIORS. THIS FOUR-COMPONENT ASSESSMENT MAKES NO PRESUMPTION THAT A CLIENT MUST HAVE DIFFICULTIES IN ANY PARTICULAR COMPONENT AREA; COMBINATIONS OF COMPONENTS ARE POSSIBLE. WITHIN THE ASSESSMENT OF ANY ONE COMPONENT, THE SELF-REPORT, PHYSIOLOGIC, OR MOTORIC ELEMENT MAY BE ESPECIALLY VALID FOR THAT COMPONENT OF SEXUAL ASSESSMENT. THE MOST VALID ELEMENT USUALLY IS THE ONE WHICH MOST ACCURATELY GENERATES AN OBSERVABLE RESPONSE CLOSELY ASSOCIATED TO THE COMPONENT MEASURED. PHYSIOLOGIC RESPONSES, FOR EXAMPLE, ARE SPECIFICALLY EFFECTIVE IN MEASURING DEVIANT SEXUAL AROUSAL SINCE ERECTIONS CAN BE CLOSELY ASSOCIATED WITH THE SEXUAL CUES PRESENTED. PROPER EVALUATION DEMANDS USE OF ALL THREE ELEMENTS, WITH EMPHASIS ON THE MOST VALID. PROBABLY THE GREATEST ADVANTAGE OF THIS ASSESSMENT SCHEMA IS THAT IT REMAINS FLUID; THE SYSTEM DOCUMENTS WHERE ANY ONE CLIENT STANDS ALONG A CONTINUM IN EACH OF THE FOUR COMPONENT AREAS, AND THE CLIENTS MOVE FROM THAT POSITION IS A RESULT OF SELF-DECISION AND THE THERAPIST'S GUIDANCE. FINALLY, THE FLUIDITY OF SUCH AN ASSESSMENT SCHEMA APPEARS TO FIT QUITE WELL WITH THE DELICATE, ETHICAL ISSUES RELATED TO WORKING WITH SEXUAL DEVIATES: WHO REALLY SPEAKS FOR THE CLIENT'S BEST INTERESTS AND IS IT THE CLIENT OR SOCIETY THAT NEEDS TO CHANGE. REFERENCES INCLUDED. (LWM)