Which term denotes a discriminative stimulus signaling reinforcement is available for a behavior?

• A. Stimulus Delta
• B. Motivating Operation
• C. Discriminative Stimulus
• D. Establishing Operation

Answer: (C)

The key idea is that a discriminative stimulus marks when reinforcement is available for a given behavior. When this stimulus is present, the learner understands that performing the target behavior will be followed by a reinforcer, so the behavior is more likely to occur in that situation. For example, a bell signaling that food is available if the dog sits makes the sit response more probable when the bell is ringing. A stimulus delta conveys the opposite—reinforcement is not available in its presence—so the behavior is less likely there. Motivating operations change how much the reinforcer matters or how motivated the learner is to obtain it, which can increase or decrease the likelihood of responding to the SD, but they don’t by themselves signal that reinforcement is currently available. An establishing operation is a type of MO that increases the value of the reinforcer. Therefore, the term that denotes a cue signaling reinforcement is available is the discriminative stimulus.