Skinner's operational conditioning theory is a fundamental part of the reinforcement principle.Skinner referred to reinforcement as any event in which conditioning increases the probability of an individual's operant response. He distinguished between two types of reinforcement: positive reinforcement and negative reinforcement. The increase in stimulus is positive reinforcement when there is an increase in the probability of an increase in a stimulus in the environment. And negative reinforcement occurs when a stimulus in the environment decreases while the probability of a behavioral response increases.
The teacher praised the students for their discipline in class is not positive reinforcement.