Social communication deficits present in some neurodevelopmental disorders, including autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), create challenges in social, academic, and adaptive functioning throughout the lifespan. Since the number of people diagnosed with ASD with comorbid ADHD is rising, it is paramount that interventions occur early and often to minimize potential difficulties. These interventions can be delivered in individual or group formats and different settings, including schools, clinics, homes, and telehealth. Unfortunately, the number of evidence-based interventions to address social communication symptomatology, while growing, remains wanting. Social Thinking, a methodology that teaches social cognition and communication through an amalgamation of three research-based theories (cognitive behavior therapy (CBT), theory of mind, and central coherence theory), is increasingly popular among practitioners from multiple fields. However, there are questions about its evidence base. The current single-case design study investigated the effects of a virtual social skills training group using Social Thinking methodology on three participants' behavior and knowledge changes in and outside the intervention setting. Results varied by participants and behaviors measured. A repeated lesson showed more significant behavioral change across participants during and outside of intervention sessions than lessons presented once. The author explains these effects, implications of the current research, and future considerations for similar research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]