This full-color clinician's manual is the authoritative guide to implementing the Joint Attention, Symbolic Play, Engagement, and Regulation (JASPER) intervention. With a strong evidence base, JASPER provides a clear, flexible structure to bolster early skills core to social communication development. The authors show how to assess 1- to 8-year-olds with autism spectrum disorder (ASD), set treatment targets, choose engaging play materials, tailor JASPER strategies to each individual, and troubleshoot common challenges. In a convenient large-size format, the manual features case examples, learning exercises, and reproducible clinical tools. At the companion website, clinicians can download and print the reproducible materials as well as a supplemental annotated bibliography.