Operant conditioning is so called because the organism has to operate on the environment to get a reward. It is also known as instrumental conditioning because the individual’s response is instrumental in obtaining a reinforcement. Reinforcement is an important concept in operant conditioning.
In order to get a reinforcement, the subject must do something. Without that, his behaviour would not be rewarded. In natural course, the leaner makes a specific responses. When the desired specific response occurs, it is reinforced, other responses are not reinforced. When reinforcement occurs on a number of occasions, the association between the response and reward is strengthened and we say that conditioning has taken place. In a typical operant conditioning experiment, a rat is placed in the Skinner box.
At first, it explores the box. The experimenter operates the lever from outside the box and releases a food pellet. When the rat sees it, it eats food. After sometimes, while exploring the box it accidentally presses the lever. It gets a food pellet on lever pressing. After some more repetitions of the responses, it learn the relationship between lever pressing and release of the food pellet.
So whenever it is hungry it directly goes and presses the lever to get the food pellet. This is how operant conditioning is established. In this example the reinforcement was positive. There can be a different type of situation where the reinforcement is an escape from something unpleasant.
Suppose a rat is placed in a box whose floor can deliver a mild shock to the rat. The lever pressing response can discontinue the shock. Through operant conditioning the rat learns to press the lever as soon as the shock comes.