The document is designed to provide practical information for teachers, parents, group home workers, work activity personnel, and others interested in developing social interaction skills and appropriate social behaviors in developmentally disabled adolescents and young adults. An introductory section discusses social problems of the developmentally disabled adolescent and young adult, such as lack of friends, inappropriate social behaviors, and poor self concept. The three-pronged training model for social skill development utilizes three methods--behavior modification; instruction with discussion, modeling, and role playing; and experimental exercises (such as group games and recreation activities). Program organization is detailed in terms of selection and grouping of participants, skills of trainers, organization of sessions, and training setting. Techniques used for assessing social skills are the Recreation-Social-Sexual interview, direct observation of the participant's behavior, and behavioral checklists/rating scales that inquire into social strengths and weaknesses. A final section of the booklet is concerned with the specific social skills addressed in the model, objectives, and sample training activities. Social skills fall primarily into three categories: interactive behavior skills, which are generally nonverbal; interpersonal communication skills, which require verbal interactions; and appropriate social behaviors, which are related to social norms. A final section contains bibliographies on scales with social skills components, on social skill development, and on adapted equipment. (SW)