The discussion emphasizes the need to be guided by theory regardless of the approach used. Clinical trials focus on diagnosis and random assignment to standardized treatments, which are most often guided by manuals and monitored for adherence. The major advantage of clinical trials is the experimental control they provide and the internal validity they ensure. Their major weaknesses include a lack of external validity in some cases, difficulties in accommodating attrition, and difficulties in coping with patient heterogeneity if factors other than the primary diagnosis have an important role in determining the outcome. Naturalistic or descriptive methodologies focus less on diagnosis and the technical aspects of treatment and more on the interpersonal and dynamic characteristics of the patient, the therapist, and the dyadic process between them. The advantage of such approaches is their external validity. The major weakness is the lack of a good basic science of human relatedness. The result is, at best, little incremental knowledge, and, at worst, unrelated "fishing" expeditions. When studying treatment of adult survivors of childhood sexual abuse, exploratory approaches are currently the most appropriate, but they must be based on small, local models. Models that consider cause, acute treatment, and strategies for maintaining long-term gains as distinct phases; control groups; and longitudinal studies are also needed. 28 references