A priority of the 2011 Interagency Autism Coordinating Council concerns ‘Identifying methods for measuring changes in core symptoms of ASD from treatment’. The underlying issue is that we have few validated measures or methods to reliably assess change in core deficits that result from interventions. Currently outcome measures for treatments focus on standardized test results (IQ, language, adaptive behavior) or reports of behaviors by parents or teachers that may indirectly assess the intervention targets. Change in core developmental difficulties are rarely assessed as an outcome of intervention; yet, they may be some of the most important measures of sustainable, meaningful change. This panel’s main learning goals are to introduce new ways to measure meaningful treatment change and to provide compelling evidence of the sensitivity of these novel methods. To this end, researchers on this panel will describe advances in autism-focused assessment, observational methods, and computing technologies that can produce valuable information about meaningful treatment change. Data will be drawn from studies of core deficits in social communication, joint engagement, and social relations in populations that include infants and toddlers with autism, underserved children assessed in schools, and minimally verbal individuals with ASD and that focus on core symptom change.