Final answer:
Reinforcement in operant conditioning increases the likelihood that a behavior will occur again, with positive reinforcement adding a pleasant stimulus and negative reinforcement removing an unwanted one.
Step-by-step explanation:
In the context of operant conditioning, reinforcement increases the likelihood of a behavior occurring again. This principle is founded on the work of B. F. Skinner and is a key component of operant conditioning, a form of learning where behaviors are influenced by their consequences. Reinforcement serves to strengthen behavior, and it can be either positive or negative. Positive reinforcement involves adding a desirable stimulus to increase a behavior, such as giving a dog a treat for sitting. On the other hand, negative reinforcement involves removing an aversive stimulus when the desired behavior occurs, like taking pain away when a person takes medication. Both forms of reinforcement aim to increase the frequency of the behavior they follow.