Billy sees a sign for a gas station; what type of antecedent is the sight of the sign?

• A. An SD
• B. Positive Reinforcement
• C. An EO
• D. An AO

Answer: (A)

Discriminative stimuli signal that reinforcement is available for a specific behavior. The gas-station sign acts as a cue that, in this environment, performing the appropriate behavior (such as stopping or pumping fuel) could lead to reinforcement. It’s not reinforcement itself, nor does it directly make the gas more desirable or change its current value. That role belongs to establishing operations (which increase the value of the reinforcer) or abolishing operations (which decrease it). The sign simply sets the occasion for the response by indicating that reinforcement is available, which is why it’s an SD.