 The 6-month Social ABCs parent-mediated intervention consists of 3 months of in-home live parent coaching and a 3-month period during which the parent implements the strategies with no further coaching. Parents implement the procedures in vivo, as they play with and follow routines of daily life with their toddlers. Research Trainers train parents using positive teaching procedures in which feedback and suggestions focus on parents strengths i.e., correct or close-to-correct implementation of the intervention procedures. The 3-month parent training program consists of 8 consecutive weeks of Active Training followed by 4 consecutive weeks of Consultation and Refresher. During the 8-week Active Training phase, individual 1.5-hour sessions are provided three times on separate days in Week 1, twice on separate days in Week 2 and once in each of Weeks 3-8, for a total of 11 training sessions. Parents are provided with written modules that form the Social ABCs Intervention Manual, through which they are led by their Research Trainer. Each visit begins with a discussion of the module and intervention targets. For the remainder of the session, parents implement the procedures with their child, while receiving feedback in vivo coaching from their Trainer. During the 4-week Consultation and Refresher phase Weeks 9-12, parents are contacted weekly by their Trainer via telephone email to trouble-shoot specific issues as needed, and the Trainer makes 2 home visits Weeks 10 and 12 in which additional video recordings of in vivo coaching are taken. 