A primary grades specialist implemented a 10-week practicum intervention designed to increase third graders' social skills by training their teachers in cooperative learning techniques and providing cooperatively structured lessons. Eight skills were addressed; these included the skills of accepting peers' ideas for group activities, completing tasks on time, and following directions. Teachers participated in eight weekly in-service sessions. These sessions concerned the research basis for using cooperative learning, a description of the concept, teacher and student roles, ideas for implementation, a management system, and cooperative lessons for students. Videos were shown that introduced cooperative learning and offered a view of students engaged in cooperative learning sessions. A "quality circle" team was organized for the purpose of brainstorming for ideas and reviewing the teacher in-service program and materials. Students were provided with lessons that were structured for cooperative learning in reading, spelling, and mathematics. It was expected that the intervention would improve students' social skills and task completion times and teachers' knowledge of techniques for teaching social skills. Practicum evaluation data indicated that the intervention was successful. Related materials, including a teacher training manual on cooperative learning, are appended to the document. (RH)