The purpose of this study is to test the effectiveness of a school-based treatment aimed at increasing language and social skills in preschool-aged children with autism spectrum disorder (ASD). Through interactive development (continually seeking educator feedback for intervention improvement) and implementation of the intervention, the investigators hope to provide a feasible and practical means for educators to work with children with ASD in real world, large scale settings. ASD preschool educators, the children enrolled in their classes, between the ages of 3 and 6 years and their families may join.

In Phase 4, KKI staff trained Delaware preschool teachers to serve as model coaches and educators through the Delaware Autism Program. Families whose children were enrolled in participating classrooms were consented through DAP using the school's consent to be videotaped. Any families who did not consent for their child to be videotaped for this training received the nonparticipant consent form currently utilized in this study and staff videotaping took every effort to keep those children out of frame when taping. This cohort involved KKI study team members training 1-2 coaches, who then trained five Delaware school teachers. The IES model was implemented in the teacher's classrooms (n= 5-10 students participating in each classroom; 20-40 children total).

In the current phase of the study, Phase 5 and 6, KKI study team members will continue the evaluation of the IES model, by testing the efficacy of the intervention model in a larger sample (Phase 5) and then analyzing the corresponding data (Phase 6). The larger efficacy study (phase 5) will be conducted on teachers and students recruited from public school districts in Maryland, Delaware, and Pennsylvania using the same IES model and recruitment methods in the previous phases.

Inclusion Criteria:

For Teachers:

- Work in an ASD preschool classroom within a cooperating Baltimore County Public School.

For Children:

• Meet Autism Diagnostic Observation Schedule-Generic (ADOS; Lord et al., 2002) and expert clinical judgment criteria for ASD
• Have an IQ or Developmental Quotient of at least 40 based on the Early Learning Composite from the Mullen Scales of Early Learning (Mullen, 1995)
• Be enrolled in a participating Baltimore County Public School ASD preschool classroom
• Be between the ages of 3 and 6 and enrolled in a participating ASD preschool classroom.

Exclusion Criteria:

Children and educators may be taken out of the study if they:

• Are unable to comply with the study protocol
• Change schools due to relocation

Children may also be taken out of this study if they:

• Sustain a head injury or other serious physical injury during the study
• Are not being brought in for testing as designated in the protocol

Individual participant data for teachers will be shared with the Delaware Autism Program to determine feasibility of model implementation. Child participant data will not be shared.