This study has the goal of furthering our understanding of measuring changes in the presentation of Autism Spectrum Disorder (ASD) symptoms over the lifetime. Specifically, we will measure subtle changes in core symptoms of ASD, including social skills and repetitive and restricted behaviors/interests through the Brief Observation of Social Communication Change (BOSCC). While other diagnostic tests (e.g. ADOS-2, ADI-R) measure these clinical symptoms, they are less sensitive to subtle changes across time that may be a result of intervention, therapy, or other developmental changes. The study will collect short video observations across age (6 months through adults, lifespan), setting (i.e. clinic, home), activity, and social partner (i.e. clinician, parent), in people with ASD, in addition to a typically developing sample at two time points (3-6 months apart, depending on the length of treatment).