ABSTRACT
The three-term contingency shows how the frequency of behavior relates to its previous consequences (Skinner, 1953):
where SD represents the discriminative stimulus, and R is the response that is either reinforced (Sr+) or punished Sr-. There are two major kinds of consequences: reinforcers, which increase behavior they follow, and punishers, which decrease behavior they follow. Both reinforcement and punishment can be classified as positive and negative. Positive and negative here do not mean good and bad; they mean adding a stimulus and removing a stimulus, respectively. Therefore, positive reinforcement is the presentation of a stimulus after a response so that the response will occur more often. Negative reinforcement is the removal of a stimulus after a response so that the response will occur more often. Similarly, positive punishment is the presentation of a
stimulus after a response so that the response will occur less often. Negative punishment is the removal of a stimulus after a response so that the response will occur less often.
