Reprints of 17 studies on approaches to ensuring full participation of handicapped students in the regular classroom are presented. The studies, carried out over a 3-year period, were intended to examine evidence on the efficacy of mainstreaming, with particular emphasis on the role of competitive, cooperative, and individualistic learning experiences on friendship, interpersonal attraction, performance, achievement, and relationships between handicapped and nonhandicapped students. The studies point out the value of the cooperative learning approach in securing active participation of handicapped students, generalizing positive relationships to free time situations, promoting achievement and self-esteem of handicapped Ss, and promoting the ability of nonhandicapped students to take the perspective of their handicapped peers. The cooperative approach is said to be easily developed and implemented and to result in benefits for both handicapped and nonhandicapped students. (The studies included severely handicapped, hearing impaired, mildly retarded, and learning disabled populations.) (CL)