This paper on trends in special education and implications for training personnel emphasizes the importance of partnerships between elementary and secondary schools and colleges of education, and specifically recommends the establishment and implementation of clinical models of teacher education and the formation of Professional Development Centers. Professional Development Centers serve as model sites for supervised clinical experiences and facilitate the transition of theory and research into practice. Staff members of Professional Development Centers must be committed to collaborative efforts in clinical preparation, applied research, and continuing professional development of all parties. The Centers should be located in a variety of socioeconomic settings and should reflect a state's population characteristics. The Center concept requires that curricula and instructional strategies be designed to model research-based practices and learning models discussed in universities' teacher preparation programs. This paper discusses qualities of clinical supervisors in Professional Development Centers, program characteristics, obstacles and inhibitors to obtaining the ideal program, and stages in moving toward this ideal. (JDD)