An expanded look at the work of B.F. Skinner
While Skinner is the best known proponent of operant conditioning, his work is largely based on the earlier work of Watson. (Remember Watson? Remember Albert?) Skinner agreed with Watson that psychology could only become a science through the study of behavior. Like Watson, Skinner was unconcerned about mentalistic events, and saw such a focus as distracting from the real work to be done.
Unlike Watson, Skinner disagreed with the classical S-R model. Behavior, he argued, is shaped by the outcome, not the antecedent. That is, Skinner believed that the organisms influence on the environment and the environment's response, was more important than any environmental stimuli.
Throughout Skinner's career, rigorous research procedures were the hallmark of his work. He steadfastly agreed with Hull that such procedures were necessary to form the basis of "good science." Skinner believed that theory was the result of good science, and not the driving force. Therefore, he instituted good research methods in the laboratory, and allowed theory to emerge. This was in sharp contrast to other theoretical approaches where theory was developed in the abstract, and then procedures were designed to demonstrate that the theory was correct.