"Pavlov's theory is known as classical conditioning. The distinticive characteristic of this form of learning is that a particular stimulus comes to elicit a response after the learning experience that it did not elicit before. Skinner (1978, 1953) calls this respondent behaviour: the response follow automatically upon the appearance of the stimulus. Skinner, however, argued that most behaviour is not to be accounted for in terms of classical conditioning, for most behaviour is operant behaviour. Operant behaviour is so called because it is behaviour that operates on the environment; we cannot normally identify any particular stimulus produces such operant responding as talking, grasping, play. Operant behaviour is emitted by the organism rather than elicited by stimuli. Skinner does not explain the learning of termsof the patterns of reinforcement that determine its occurence. In classical conditioning what reinforces the behaviour is the unconditioned stimulus, but what rein...