A cooperative professional evaluation system developed by the Southwest Cook County (Illinois) Cooperative Association for Special Education is described. The development of the system is outlined including writing of generic and specific job descriptions and determination of a philosophy of evaluation which identified the following purposes: improving special education, identifying areas of growth for each professional, and aiding administrative decisions. The final process involves a pass-fail rating system for basic competencies, a specific remedial program for teachers who do not achieve the acceptable rating, and an individual self-evaluation in which supervisors and the individual identify areas of growth and areas needing attention for the following year. The system accomplishes such objectives as reduction of morale problems caused by the previous norm-referenced/comparative system, focus on staff improvement, and consistency with the human resources model of supervision. (DB)