Predictability in Reinforcement
Schedules of reinforcement dictate when a reinforcer is delivered. The distinction between Fixed and Variable schedules is a classic exam topic.
Fixed Schedules
Reinforcement happens after a set number. "Fixed" means constant. For example, a Fixed Ratio 3 (FR3) means every 3rd response is reinforced. The learner knows exactly when the reward is coming. It produces a "stair-step" pattern of responding (pause after reinforcement).
Variable Schedules
Reinforcement happens around an average number. "Variable" means changing. A Variable Ratio 3 (VR3) means reinforcement comes on average every 3rd response, but it could be after 1, then 5, then 3. This unpredictability creates a high, steady rate of responding without pauses. It is like a slot machine.
Memory Trick
Fixed = Predictable (Pause). Variable = Unpredictable (No Pause). Variable Ratio is the strongest schedule for maintaining behavior.