What is an example of a situation that illustrates stimulus change (S delta)?

Stimulus change, specifically S delta, refers to a stimulus that signals the absence of reinforcement for a particular behavior. In the context of the provided example, the scenario of getting cash only from a soda machine instead of using a card illustrates this concept well.

In this situation, the soda machine indicates that using cash is the desired behavior due to the absence of the option to use a card. Therefore, the machine serves as a cue or signal indicating that the usual behavior of using a card will not be reinforced; instead, it prompts a different behavior—using cash—to obtain the desired outcome.

The other options do not represent this concept effectively. For instance, seeing a stop sign, noticing changes in appearance, and responding to familiar sounds involve recognition or response to stimuli but do not convey the absence of reinforcement for a specific behavior, which is central to understanding S delta.