The special educational needs of children with autism spectrum disorders (ASD) are extensive. Educators face practical problems such as targeting the core social and communication deficits of children with ASD in group instructional settings. For example, children with ASD exhibit problems with interpersonal synchrony, which requires socially appropriate initiations and responsivity to others. To address these concerns, there is a need for evidence-based, cost-effective educational and service delivery models to treat these children. The purpose of this research is to develop and document the feasibility and promise of a social and communication curriculum supplement, Early Achievements. This intervention will be adapted for preschoolers from an intervention originally targeting toddlers. The ultimate aim of the project is to develop a preschool supplementary intervention targeting core social and communication deficits of ASD that can be integrated with existing academic curricula throughout the school day. It will include guidelines for intervention materials, activities, and instructional strategies based on Pivotal Response Training paired with strategies that promote interpersonal synchrony and engagement. The research will also examine the feasibility of the intervention, the promise of the intervention for changing instructional practices and child skills, and whether the results are impacted by the inclusiveness of the classroom placement or the severity of the of the child's impairment.