Autism is a lifelong developmental disability that affects how people perceive the world and interact with others.Autism is a lifelong developmental disability that affects how people perceive the world and interact with others.

DIR is the Developmental, Individual-differences, & Relationship-based model (pronounced saying each letter as an initialism: D.I.R.).

A speech disorder refers to a problem with the actual production of sounds. A language disorder refers to a problem understanding or putting words together to communicate ideas.

Behavior analysis focuses on the principles that explain how learning takes place. Positive reinforcement is one such principle.