In a fixed-interval schedule, reinforcement is provided only after a specific, predictable amount of time has passed. This often leads to a 'scalloped' response pattern where performance drops immediately after reinforcement and increases only as the time for the next reinforcement approaches, resulting in lower overall rates compared to ratio schedules.

Extinction in operant conditioning occurs when a previously reinforced behavior is no longer reinforced, leading to a decline in the frequency of that behavior over time until it eventually disappears.

Positive reinforcement increases the likelihood of a behavior by adding a desirable stimulus after the response occurs. Conversely, negative reinforcement increases the likelihood of a behavior by removing or avoiding an aversive stimulus. Both processes serve to strengthen the frequency of the target behavior, but they differ fundamentally in whether they involve the presentation or the withdrawal of a stimulus.

Operant conditioning, as developed by B.F. Skinner, relies on the principles of reinforcement and punishment to modify behavior. Reinforcement (reward) increases the likelihood of a behavior being repeated, while punishment decreases the likelihood of a behavior being repeated. Both are essential components for shaping and maintaining behavioral patterns.

A secondary reinforcer, often referred to as a conditioned reinforcer, is a stimulus that gains its reinforcing power through its association with a primary reinforcer. While primary reinforcers satisfy biological needs like food or water, secondary reinforcers—such as money, grades, or praise—acquire value through classical conditioning processes. They are essential in shaping behavior within complex social and educational environments.

Primary reinforcers are biologically important stimuli like food that satisfy basic needs. Secondary (or conditioned) reinforcers, such as money, acquire their reinforcing value through association with primary reinforcers or other established rewards.

Punishment is a core concept in operant conditioning designed to reduce the frequency of a specific behavior. Positive punishment involves adding an unpleasant stimulus, while negative punishment involves removing a desirable one. Both methods serve the same functional goal of behavior suppression, distinguishing them from reinforcement, which always aims to increase behavior frequency.

A variable interval schedule is a type of operant conditioning where reinforcement is provided after an unpredictable, varying amount of time has passed. Because the timing of the reward is inconsistent, this schedule typically produces a slow, steady rate of response, as the subject cannot predict exactly when the next reinforcement will occur.

Reinforcement is a core concept in operant conditioning defined by its effect: increasing the frequency or likelihood of a behavior. It can be positive (adding a reward) or negative (removing an aversive stimulus).

A variable-ratio schedule provides reinforcement after an unpredictable number of responses. This schedule is highly resistant to extinction and produces a high, steady rate of response because the subject never knows exactly how many attempts are required to receive the next reward. Slot machines are the classic example of this, as the payout frequency varies, keeping the player engaged.