5.15 : Reinforcement Schedules

Positive reinforcement is a powerful method for teaching new behaviors to both animals and humans. B.F. Skinner demonstrated this with his experiments using rats in a Skinner box. When a rat pressed a lever, it received a food pellet. This immediate reward encouraged the rat to repeat the behavior. This method, where a reward follows every instance of the behavior, is known as continuous reinforcement. It is highly effective for establishing new behaviors quickly.

Once a behavior is learned, trainers often switch to partial reinforcement, where rewards are given intermittently rather than every time. Partial reinforcement can be classified into four types: fixed interval, variable interval, fixed ratio, and variable ratio.

1. Fixed Interval (FI) Schedule: Rewards are provided after a set amount of time. For example, an employee receives a performance review and potential raise every six months, increasing productivity as the review date nears. Behavior tends to increase as the time for the next reward approaches and may decrease just after receiving the reward.
2. Variable Interval (VI) Schedule: Rewards are given after varying amounts of time, making it unpredictable. This schedule encourages consistent behavior because the reward can come at any time. For instance, employees might receive surprise bonuses for keeping a restaurant clean.
3. Fixed Ratio (FR) Schedule: Rewards are given after a set number of responses. This schedule motivates high rates of response. However, there may be a brief pause in behavior directly after receiving the reward. For example, a salesperson earns a commission for every five glasses sold, prompting them to sell more glasses to earn more commissions.
4. Variable Ratio (VR) Schedule: The number of responses required for a reward varies, creating a high and steady rate of response. This schedule is most effective and resistant to extinction. Gambling is a prime example, where the uncertainty of winning keeps players engaged.

Understanding these reinforcement schedules helps in effectively shaping and maintaining desired behaviors in both educational and training settings.