This collection of 11 articles focuses on integrating handicapped and nonhandicapped children in preschool programs. Article 1 presents arguments for preschool integration. Article 2 discusses research on peer interaction and mixed-age socialization. Article 3 advocates a behavior analysis and operant conditioning approach to studying and influencing peer interactions. In Article 4, four preschool model programs -- behavioral, normal developmental, cognitive developmental and cognitive learning -- are described. Article 5 specifies dimensions of integrated preschool programs which promote development of handicapped children. In Article 6, the feasibility of training young delayed children to imitate behavior of nondelayed classmates is discussed. Article 7 reports studies of an integrated, cognitively oriented preschool program. Article 8 reports on integration in a day care center. Article 9 discusses integrating the hearing-impaired child. In Article 10, the mainstreaming of handicapped preschool and kindergarten-age children into open structure classrooms is described. Article 11 describes the merger of a mental retardation agency's early education services with community preschool programs. (Author/RH)