Investigators will enroll preschoolers with the minimal responder profile who are scheduled to begin the PRT-based public EI program. Consenting parents will be offered a virtual intervention in which they will be randomized to 1 of 2 arms to receive coaching in either (a) PRIMeR intervention, designed to target areas of weakness in the minimal responder profile, or (b) PRT, the treatment model used in the EI program. Coaching will take place on a virtual (video-conferencing) platform. Each child's progress on treatment targets will be assessed in a single case experimental design (SCED) using data from blind-coded video-recordings of parent-child play episodes using a standard set of toys. Overall study effects will be based on aggregated data for an anticipated n of 20 participants assigned to each arm (4 SCED series with 5 participants each contributing to each arm). The primary outcome is gains in children's social initiations (video-coded); the secondary outcome is gains in children's communication levels (multi-method assessment). Mixed methods will be used to evaluate aspects of parents' experiences,
Early intervention (EI) using naturalistic behavioural methods have shown benefits for the development of communication and other skills for young children with autism spectrum disorder. The publicly funded autism EI program in Nova Scotia (NS) is based on such a method, Pivotal Response Treatment (PRT), and pre-post studies indicate benefits for children and families. However, not all children benefit equally. In this study, the investigators test the efficacy of a brief parent-mediated intervention designed to prime responsivity to PRT in children with a minimal responder profile derived from previous studies of the PRT-based EI program.