There is general consensus among members of the autism research and treatment communities that treatment for autism spectrum disorders should focus on improving social interactions and communication skills. Dr. Charman and his colleagues have used a test called the Classroom Observation Schedule to Measure Intentional Communication (COSMIC) as a way to measure communication ability. Researchers watch a videotape of children in a real-life setting such as the classroom targeting interaction of children, their peers and their teachers. In this study, the COSMIC will be integrated into an ongoing trial called the Preschool Autism Communication Trial (PACT). PACT, as originally funded, has no evaluation of social and communication behavior in an everyday situation. This study will fund post-doctoral fellow Sally Clifford to use COSMIC to evaluate a subgroup of 48 PACT participants in two everyday school activities: one in the classroom interacting with a teacher and one on the playground interacting with peers. Her findings will provide support for any improvements found from other outcome measures of the PACT study and will help validate COSMIC as a tool for future treatment outcome studies. What this means for people with autism: This study will add a critical outcome measure to one of the largest ever randomized clinical trials of the psychosocial behavioral treatment for autism. Specifically, it will provide information about how a treatment to improve social and communication skills in children with autism translates into the real world.