6.11 Schedules of Reinforcement

Schedules of Reinforcement

Introduction to Schedules of Reinforcement

• Schedules of reinforcement are the rules that determine when reinforcement becomes available.

• The central question is: "When do we expect a reward?"

Types of Schedules

1. Continuous Reinforcement

   • Definition: Reinforcement occurs every time a behavior is performed.

   • Example: Vending machines operate under continuous reinforcement; every time money is inserted, and a selection is made, the desired product is dispensed, assuming proper operation.

2. Partial Reinforcement

   • Definition: Reinforcement occurs after an intermittent number of behaviors or after an intermittent time period.

   • Real-world examples:

     • VLTs (Video Lottery Terminals) and slot machines, which do not dispense rewards every time the lever is pulled.

     • In gambling, rewards might occur, for instance, every hundredth or thousandth trial.

Subtypes of Partial Reinforcement

1. Ratio vs. Interval Schedules

   • Ratio Schedule: Reinforcement based on the number of behaviors performed.

   • Interval Schedule: Reinforcement based on the amount of time that has passed.

   • Further breakdown into fixed and variable schedules:

     • Fixed Schedule: More predictable.

     • Variable Schedule: More variable.

Fixed Schedules

1. Fixed Ratio Schedule

• Definition: Reinforcement is delivered after a predictable number of behaviors.

• Example:

  • In the context of an operant chamber with a rat: If set to a fixed ratio of 10, the rat must press a lever 10 times to receive food reinforcement.

  • After each 10 lever presses, food is dispensed, encouraging steady behavior.

• Real-World Example:

  • Loyalty cards used in stores where customers receive a stamp or punch for each purchase. After a specific number of visits (e.g., 10), they receive a free item.

2. Fixed Interval Schedule

• Definition: Reinforcement occurs after a predictable amount of time has elapsed.

• Example:

  • In an operant box with a rat, if set to a fixed interval of 100 seconds, the rat must wait 100 seconds before pressing the lever to receive food. This cycle repeats, requiring another 100 seconds wait before reinforcement is available again.

• Scalloped Pattern of Responding:

  • Describes the typical response pattern.

  • Initially, slow responding occurs as the time interval progresses, followed by a steep ramp-up in activity as the time for reinforcement approaches, leading to a predictable shape in responding behavior.

• Real-World Example:

  • Mobile games like Pokémon Go often implement fixed interval schedules; for instance, spinning a Pokéstop provides rewards only after a set time interval (e.g., after a five-minute wait, the player can receive items again).

  • Study behavior association: Students often exhibit scalloped responding, ramping up study habits as exams approach, followed by declines after exams are completed.

Conclusion

• Understanding reinforcement schedules helps explain behaviors in both controlled environments and real-world scenarios. The concepts are applicable across various aspects of behavior, including gambling, shopping habits, and learning behaviors in educational settings.