Rapid changes in mental health services have brought service delivery systems into conflict with many mental health practitioners' methods of practice. Optimal design and modification of mental health delivery systems requires knowledge of the effects of service system features on therapists' practices and job-related outcomes. Practitioners are the main point of contact between service providers and consumers, however little is known about relationships between service contexts, models of practice, and practitioner outcomes. What therapists think about therapy is an important and relatively unexamined factor in these relationships. The proposed study will examine the role of therapists' models of treatment as a mediator of the effects of service delivery context upon therapists' work-related outcomes. Models of treatment is a multi-dimensional construct comprised of therapists' thoughts and feelings related to the practice of therapy. Understanding the relationship between therapists' models of treatment and their practices and work-related outcomes has practical and theoretical value. This information can enhance design of services and training programs to improve practitioner effectiveness in various settings. In addition, articulating the relationship between therapists' ideas, work settings, and practice can elucidate a mechanism by which practice contexts interact with individual variables to produce outcomes relevant to service provision. Therapists' models of treatment will be assessed using a measure to be developed as part of the proposed project. A sample of 300 Massachusetts-based psychologists and social workers will be drawn from the membership registries of the American Psychological Association, the National Association of Social Workers, and the Association of Black Social Workers. Relationships will be examined between practice setting, models of treatment, and therapists' practices and outcomes. Therapist outcome variables relevant to service provision that will be examined include job satisfaction, burnout, utilization rates, and therapy practice patterns. It is hypothesized that model of treatment will account for the effects of service context on job related outcomes and therapy practices.