The final report summarizes three studies on the efficacy of preschool programs in which handicapped and nonhandicapped children are integrated. In the first section, analyses of the social interaction of 37 4- to 6-year old children are presented. Among results cited are that nonhandicapped and mildly handicapped Ss interacted more frequently with each other than expected on the basis of availability and less frequently than expected with moderately and severely handicapped children. The second study describes a tutoring program in which eight nonhandicapped children served as change agents for 12 less advanced children. The final section describes a series of case studies involving 11 pairs of children. Among major conclusions cited is the feasibility of direct instructional interaction in free play settings between mildly handicapped and nonhandicapped children. (CL)