Overview
This lecture explains partial reinforcement schedules in operant conditioning, detailing the four main types and their effects on maintaining learned behaviors.
Partial Reinforcement Schedules
- Partial reinforcement means a behavior is reinforced only some of the time, not after every response.
- Partial reinforcement leads to greater resistance to extinction than continuous reinforcement.
- B.F. Skinner identified these schedules through animal studies, but they apply to humans as well.
Understanding the Terminology
- "Ratio" schedules are based on the number of responses made.
- "Interval" schedules are based on the passage of time.
- Each schedule can be either "fixed" (consistent) or "variable" (changing), creating four types.
The Four Schedules of Partial Reinforcement
- Fixed Ratio (FR): Reinforcement is given after a set number of responses (e.g., bonus for every 5 cars sold).
- Fixed Interval (FI): Reinforcement is given after a set time period (e.g., paycheck every 2 weeks).
- Variable Ratio (VR): Reinforcement is given after an average number of responses, but the exact number varies (e.g., slot machines).
- Variable Interval (VI): Reinforcement is given after a variable amount of time has passed (e.g., random supervisor visits).
Behavioral Effects of Each Schedule
- Fixed ratio produces a high rate of response as reinforcement depends only on performance.
- Fixed interval often leads to slower response rates since reinforcement is time-based, not dependent on effort.
- Variable ratio leads to high and steady response rates due to unpredictability of reward.
- Variable interval produces regular, steady responding because reinforcement times are unpredictable.
Key Terms & Definitions
- Partial Reinforcement — Reinforcing behavior only some of the time.
- Extinction — The fading of a learned behavior when reinforcement stops.
- Fixed Ratio (FR) Schedule — Reinforcement after a set number of responses.
- Fixed Interval (FI) Schedule — Reinforcement after a fixed amount of time.
- Variable Ratio (VR) Schedule — Reinforcement after a varying number of responses, averaging a certain number.
- Variable Interval (VI) Schedule — Reinforcement after varying time intervals.
Action Items / Next Steps
- Review personal experiences and label them with the four types of reinforcement schedules.
- Study definitions and characteristics of each schedule for exam preparation.