Operant Conditioning

The central purpose of education is to help students to learn. The basic processes that produce learning have been investigated in the laboratory under the heading of conditioning. The technical term conditioning is used to distinguish between behavioral changes that are conditional upon—that is, dependent upon—individual experience and those that are largely independent of experience, such as salivating when a sweet substance stimulates the tongue or blinking when an object rapidly approaches the eye. This entry describes the two factors that laboratory research has identified as essential for conditioning. The entry then explores some of the implications of what is known about basic conditioning processes for learning outside the laboratory. The carefully controlled methods of the laboratory most often use nonhuman animals, but they are necessary to uncover fundamental learning processes. However, these basic processes have been confirmed in later research with humans. Following their discovery, they have been used to facilitate learning in the less controlled and more complex environments of the everyday world. Application of basic principles to behavior outside the laboratory always involves additional knowledge of the specific fields to which they are applied.

Two types of laboratory procedures have been used to study learning processes—operant conditioning and classical conditioning. The two procedures have in common the fact that each presents the learner with an environmental event (a stimulus) that already elicits some behavior. Common laboratory examples are food that elicits salivation and a puff of air to the eye that elicits blinking. A stimulus that already elicits a readily identified response provides the experimenter with a response that can be used to track the progress of learning.

The two procedures differ with regard to what kind of event precedes the eliciting stimulus. In the operant procedure, a response precedes the eliciting stimulus such as when a lever-pressing response is followed by the presentation of food. In the classical procedure, another stimulus precedes the eliciting stimulus, such as when the sound of a tone is followed by food, to use another laboratory example. In the classical procedure, the behavioral change (learning) that occurs is an increase in the strength of the elicited response to a new stimulus. Continuing with the laboratory example, after several tone-food pairings, salivation begins to occur during the tone even before the food is presented on that pairing. In the operant procedure, the behavioral change involves not only an increase in the strength of the elicited response but also in the strength of whatever response precedes the eliciting stimulus and its elicited response. For example, after several pairings of lever pressing with food, not only does salivation increase when the animal sees the lever, but the likelihood of pressing the lever also increases.

As the foregoing examples illustrate, the classical procedure is limited to changing the stimuli that guide a response that can already be elicited: The tone comes to evoke salivation, a response that was originally elicited by food. The operant procedure is much more versatile because almost any behavior of which the learner is capable can become guided by the environment: The sight of the lever guides not only salivation but lever pressing. Using an operant procedure, the strength of any one of a large number of responses could have been changed if they had preceded the food—pulling a chain, vocalizing, running down a path, and so on. The responses that precede the eliciting stimulus are called operants to emphasize that they operate on the environment to produce the eliciting stimulus. Because of the greater scope of the operant procedure for changing behavior, findings from this procedure have more profound implications for understanding the learning process, particularly the conditioning of complex behavior.

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