Understanding Discriminative Stimulus (SD) in ABA: Insights from Two Decades of Progressive Practice

After twenty years in the field of Applied Behavior Analysis as the founder of Practical Solutions for Behavior and Instruction LLC (PSBI), I've witnessed firsthand how our understanding and application of ABA principles have evolved. Today, I want to share insights about one of the most fundamental concepts in ABA therapy: the discriminative stimulus (SD). This concept remains crucial in progressive ABA approaches, yet its application has become more nuanced, flexible, and person-centered over the years. What is a Discriminative Stimulus (SD)? At its core, a discriminative stimulus (SD) is a specific environmental cue or event that signals the availability of reinforcement for a particular behavior 1 . In simpler terms, an SD tells an individual that if they perform a certain action in response to this cue, they will likely receive a desired consequence or reward. This concept is foundational to ABA therapy and is based on the principles of operant conditioning, where behaviors ...