Positive reinforcement involves increasing the likelihood of a behavior by presenting a pleasant stimulus after the behavior occurs.

Negative reinforcement involves increasing the likelihood of a behavior by removing an unpleasant stimulus after the behavior occurs.

Punishment involves decreasing the likelihood of a behavior by presenting an unpleasant stimulus after the behavior occurs.

Positive punishment involves presenting an unpleasant stimulus after an undesired behavior occurs.

Negative punishment involves removing a pleasant stimulus after an undesired behavior occurs.

Positive reinforcement is generally considered to be a more effective form of reinforcement than negative reinforcement or punishment.

Positive punishment is generally considered to be a more effective form of punishment than negative punishment or ignoring.

A conditioned reinforcer is a stimulus that initially does not have reinforcing properties but becomes reinforcing after being paired with a primary reinforcer.

A conditioned punisher is a stimulus that initially does not have punishing properties but becomes punishing after being paired with a primary punisher.

Operant conditioning is based on the principle that behavior is shaped by its consequences.

Operant conditioning schedules determine how often a reinforcer is presented after a desired behavior occurs.

Intermittent reinforcement schedules are schedules in which a reinforcer is not presented after every desired behavior occurs.

Fixed-interval schedules are schedules in which a reinforcer is presented after a fixed amount of time has passed.

Variable-interval schedules are schedules in which a reinforcer is presented after a variable amount of time has passed.

Fixed-ratio schedules are schedules in which a reinforcer is presented after a fixed number of responses have been made.

Variable-ratio schedules are schedules in which a reinforcer is presented after a variable number of responses have been made.