This project conducted a series of 11 studies over a period of 3 years to investigate the social skill competence of approximately 200 upper elementary and middle school children with serious emotional disturbances. The project identified a set of social tasks which proved critical in discriminating between socially competent and incompetent children; developed measures that reliably identified behaviors children use in negotiating problematic social tasks; and incorporated critical social tasks, situations, and behaviors into the development and evaluation of a social skills instructional package. The efficacy and validity of the identification and treatment system are evaluated in terms of changes in the judgments of persons familiar with the children with serious emotional disturbances, changes in directly observable social behavior, and the degree to which those changes facilitated the integration of the children into regular education settings. The report includes summaries of each of the studies. Appendices include study findings, including lists of social tasks that identify the socially incompetent child, a list of social tasks that are difficult for children, a critical task taxonomy, the interview form used to interview the students, and a description of a model intervention for social skills instruction. Appendices also include the following papers: "Determining Social Tasks: A Preliminary Report" (Richard S. Neel and Nancy Meadows); "Creating an Initial Critical Social Task Taxonomy" (Susan G. Gelhar); and "Replacement Behaviors: A Strategy for Teaching Social Skills to Children with Behavior Problems" (Richard S. Neel and K. Kay Cessna). (Contains 53 references.) (CR)