Evaluation of the Early Start Denver Model (ESDM) in an Inclusive Preschool Setting.

The Early Start Denver Model (ESDM) is a routines-based naturalistic developmental behavioural intervention for children with, or at risk for ASD under the age of 5. See Rogers and Dawson's (2010) manual: Early Start Denver Model for Young Children with Autism for more information. The intervention for this research is a simplified version of the ESDM, where ESDM techniques will be implemented during a selected period of the day to target specific behaviours, rather than embedded into all routines and interactions to target many behaviours, as with traditional ESDM. The intervention will consist of 3 x 60 minute sessions per week (totaling 180 minutes per week) of ESDM teaching delivered to young children with ASD by a therapist who is trained in the ESDM (Arm 1) or their regular preschool teacher (Arm 2), who will receive a brief ESDM training package before delivering the intervention. This training package will be specifically designed for this study. All sessions will take place at the child’s regular preschool and the intervention will be embedded in regular preschool activities and routines so may consist of one-on-one, small group and/or whole class teaching, depending on the child's specific target behaviour(s) and the period of the day when the intervention is implemented. The materials used during the intervention will be those that are typically available in each preschool. Prior to the introduction of the intervention, the researcher will work with each participant’s teachers and parents to define specific communication and social behaviours to target during the intervention. During each 60-minute ESDM therapy session, the child's individually defined goals will be embedded into the interventionist’s play with the child and will taught by applying the following behaviour analytic teaching principles: (a) the delivery of frequent learning opportunities, (b) delivery of clear antecedents, (c) the use of reinforcement, and (d) the use of instructional strategies such as prompting, shaping, chaining, and fading. At the beginning of each session, the therapist will greet the child and then allow him or her to verbally or non-verbally (e.g. leading the adult to the activity or object, pointing) choose the first activity, either by presenting a limited choice of two options or allowing the child to choose any toy or activity. Teaching will occur through the use of two types of routines: sensory social routines, in which the interventionist will play with the child without an object (e.g. songs, chase, tickles), or using special sensory objects operated by the interventionist alone (e.g. balloons, bubbles, shaving foam); and joint activity routines, in which the therapist and the child will play together with an object (e.g. blocks, books, balls). Throughout these routines, the interventionist will maintain a positive affect, employ strategies to maximise the child’s motivation (e.g., offering choices, following the child’s lead, and being sensitive and responsive to all attempts at communication), and make conscious attempts to attract and maintain the child’s attention to his/her face, voice, and actions. When the interventionist determines that there are no more learning opportunities during the chosen activity, the child seems bored, or the child initiates finishing an activity, the therapist will instruct the child to tidy up and, once the child has done so, he or she will select a new activity. Sessions will be terminated after one hour or when the interventionist determines from the child’s behaviour that he or she no longer wants to continue. Adherence to intervention will be monitored through recording of participants' session attendance and interventionist's fidelity of implementation.