Which term describes a stimulus that increases the likelihood of a response when presented?

The term that describes a stimulus that increases the likelihood of a response when presented is a reinforcer. In the context of behavior analysis, a reinforcer is any stimulus that, when it follows a behavior, increases the probability of that behavior occurring again in the future. This process is fundamental to operant conditioning, where behaviors can be strengthened through the introduction of certain stimuli that have reinforcing properties.

Reinforcers can be positive or negative. Positive reinforcement involves presenting a pleasant stimulus following a desired behavior, while negative reinforcement involves the removal of an aversive stimulus. Both types result in an increase in the frequency of the target behavior. The concept of reinforcement is crucial in behavior modification and skill acquisition, as it shapes how behaviors are learned and maintained.

Other options like conditioned stimulus and discriminative stimulus are related to different principles in behavior analysis. A conditioned stimulus is associated with an unconditioned stimulus and elicits a conditioned response but does not directly impact behavior in the same way a reinforcer does. A discriminative stimulus signals the availability of reinforcement contingent upon the performance of a specific behavior, but does not itself increase the likelihood of the behavior; it merely indicates that reinforcement is possible. A punisher, on the other hand, decreases the likelihood of