Final answer:
Positive reinforcement in a variable ratio schedule is exemplified by slot machines, which reward players unpredictably and maintain high engagement. Fixed ratio schedules, by contrast, reward a set number of responses, leading to a predictable behavior pattern with pauses after reinforcement.
Step-by-step explanation:
An example of positive reinforcement in a variable ratio schedule is the way slot machines reward gamblers with money. With a variable ratio schedule, the number of responses required for a reward changes, which keeps gamblers playing because the next win could occur at any time after pulling the lever or pressing the button; this unpredictability leads to a high and steady rate of response. It is a powerful method of maintaining behavior because the reinforcement is based on an unpredictable number of responses, creating a scenario where the behavior is resistant to extinction. It's quite different from a fixed ratio schedule where a set number of responses must occur before a behavior is rewarded, encouraging a predictable pattern of behavior with a short pause after each reinforcement.
In contrast, a fixed interval reinforcement schedule rewards behavior after a set amount of time, regardless of how many responses occur. This schedule produces a scallop-shaped response pattern, which indicates a significant pause after reinforcement, as people tend to wait for the predictable time when reinforcement will be available. Thus, these different schedules of reinforcement can significantly affect how behavior is learned and maintained.