Q.Define operant conditioning. Discuss the factors that influence the course of operant conditioning.

Operant, or instrumental, conditioning was first investigated by B.F. Skinner, who studied "operants" — voluntary behaviours or responses that an organism emits under its own control, so called because the organism actively operates on its environment to produce them, unlike the automatic reflexes studied in classical conditioning. Conditioning of such voluntary behaviour is called operant conditioning. Skinner's classic studies used rats and pigeons placed in a specially designed chamber, the Skinner Box, containing a lever connected to a food-dispensing mechanism. A hungry rat placed in the box would explore, accidentally press the lever, and receive a food pellet; with repeated trials, the time the rat took to press the lever after being placed in the box grew progressively shorter, until it pressed the lever almost immediately — at which point conditioning is considered established. Since lever pressing is instrumental in obtaining the food, this kind of learning is also called instrumental conditioning; everyday instances include children learning to say "please" to get favours, or learning to locate a hidden jar of sweets.

Operant conditioning is fundamentally a matter of learning through consequences, and these consequences are called reinforcers — any stimulus or event that increases the probability that the response producing it will occur again. Reinforcement is of two types: positive reinforcement uses pleasant consequences (food, praise, money, information) that strengthen the preceding response; negative reinforcement involves the removal of, or escape from, an unpleasant or painful stimulus, which likewise strengthens the response that achieved that removal (wearing a seatbelt to avoid injury or a fine). Negative reinforcement must not be confused with punishment — punishment suppresses a response, generally only temporarily, and can even create dislike of the punisher, whereas negative reinforcement strengthens an avoidance or escape response.

Beyond the basic type of reinforcement, several further factors, or determinants, shape how quickly and strongly operant conditioning is established. These include the number of reinforced trials, the amount and quality of reinforcement (superior reinforcers accelerate learning more than inferior ones), and — very importantly — the schedule of reinforcement: continuous reinforcement (every response reinforced) produces high responding but rapid extinction once reinforcement stops, whereas intermittent or partial reinforcement (only some responses reinforced) produces high, persistent responding that is considerably more resistant to extinction — the well-documented partial reinforcement effect. Finally, delay in delivering reinforcement dramatically reduces its effectiveness, since immediate, smaller rewards are consistently preferred over larger, delayed ones. Together, these determinants explain why operant behaviour in real life — from a child's habits to workplace performance — can be shaped, strengthened, or gradually eliminated by deliberately managing its consequences.