An autism assessment involves a multi-faceted evaluation by specialists (pediatricians, psychologists, speech therapists) using observations, parent interviews, developmental history, and standardized tools like the ADOS and M-CHAT-R to diagnose Autism Spectrum Disorder (ASD), focusing on social communication, interaction, and repetitive behaviors, with early screening by pediatricians often being the first step to identify potential needs for deeper evaluation, say the Centers for Disease Control and Prevention and Autism Speaks.