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May 2011

From the National Center for Special Education Research (NCSER)

RCT Demonstrates the Efficacy of the LEAP Model of Early Intervention for Young Children with Autism Spectrum Disorders

The LEAP Model — How it Works

In the LEAP model, typically developing children are taught how to use facilitative social and communicative initiations with their peers with autism, which in turn leads to higher rates of communicative interactions for the children with ASD. The program can be embedded within existing high-quality preschool models and curricula designed for typically developing children.

The intervention relies on naturally occurring incidental teaching, which can lead to more cost-effective treatment than direct one-to-one instruction. For example, if a child with ASD chooses to play with toy blocks during free choice time, teachers might take this opportunity to teach colors, shapes, and concepts such as big and small that relate directly to the toy blocks and the child's ongoing interests.

The intervention also includes a parent skills training component aimed at teaching parents to use communication skills with their child in naturalistic contexts and decreasing the stress experienced by the family.

In an initial RCT evaluation of LEAP, compared with a "business-as-usual" preschool model, children in LEAP were found to show such positive gains in multiple areas of development (symptom reduction, social skills, cognition and language) that after 2 years, random assignment of children into treatment and comparison conditions was suspended for ethical reasons.

Research on Autism Spectrum Disorders (ASD) and the development of interventions for children with autism have expanded greatly in recent years, though most comprehensive interventions have not received systematic, scientific evaluation. One of the few exceptions is LEAP (Learning Experiences…An Alternative Program for Preschoolers and Parents), a comprehensive intervention for preschool children with autism, developed by Phillip Strain in 1981, that uses a variety of science-based learning techniques.

Although LEAP had been shown to improve child outcomes in a prior evaluation, the developers recently implemented a new experimental evaluation comparing full LEAP implementation to a reduced model based only on access to materials. With funding from the National Center for Special Education Research, principal investigator Phillip Strain and his research team conducted a randomized controlled trial (RCT) comparing classroom implementation of LEAP with training and mentoring by LEAP staff to classrooms in which teachers were only provided with the usual LEAP training manuals and materials. They found that providing preschool teachers with LEAP training and mentoring resulted in greater fidelity of implementation and more positive child outcomes when compared to teachers who were only given the training manuals and materials.

In an article to be published this summer in Topics in Early Childhood Special Education, Phillip Strain and colleague Ted Bovey report on this recent NCSER-funded experimental evaluation of the LEAP model. For this study, the LEAP model was implemented by existing preschool staff in inclusive preschool settings around the United States. Programs, matched on characteristics such as number of days per week and adult-child ratio, were randomly assigned to two groups. Preschool staff received either the full-scale, 2-year LEAP training and mentoring (treatment group), or the commercially available LEAP intervention manuals and training materials only (comparison group).

The intervention was implemented with high fidelity in the treatment group, with a much higher percentage of program components in place than in the comparison group. Although equivalent on all measures prior to intervention, children in the treatment group demonstrated greater developmental gains in cognition and language, reduction in autism symptom severity, growth in social skills, and reduction in problem behavior compared to children in the manual-only group after the intervention. Furthermore, within the treatment group, children who experienced the intervention implemented with greater fidelity also experienced the most positive outcomes.

This 4-year project was funded with a $1.8 million grant from IES. Learn more about the project at

More details about the results can be found in Strain, P.S., and Bovey, E.H. (in press). Randomized, Controlled Trial of the LEAP Model. Topics in Early Childhood Special Education.