In behavior analysis, which describes an SD?

• A. An antecedent stimulus that indicates reinforcement is available for a given behavior
• B. A consequence that decreases the likelihood of a behavior occurring in the future
• C. An antecedent stimulus that assists a client in engaging in a desired behavior
• D. A consequence that increases the likelihood of a behavior occurring in the future

Answer: (A)

A discriminative stimulus is an antecedent cue that signals reinforcement is available for a particular behavior. When this stimulus is in place, the person is more likely to perform the behavior because reinforcement can be obtained if the behavior occurs. It’s about the signal that a reinforcement contingency is in effect in that setting.

Think of a teacher saying, “If you raise your hand and answer correctly, you’ll receive praise.” The presence of that cue indicates reinforcement can follow the target behavior, so the student is more likely to raise their hand.

This differs from a motivating operation, which changes how much the learner wants the reinforcement in the moment, and from a signal that reinforcement is not available (SΔ), which would make the behavior less likely. A prompt can help evoke a behavior, but the SD specifically signals that reinforcement is available for that behavior.