How Do Schedules of Reinforcment Affect Learning?

Skinner discovered schedules of reinforcement. Our book defines a schedule of reinforcement as "a specific pattern of presentation of reinforcers over time". Rather than giving a reinforcement (i.e. a food pellet) after every response (i.e. a lever press), Skinner fixed the operant conditioning chamber to give a reinforcement only after 2 or 3 responses. This is called a partial reinforcement schedule and is more resistant to extinction. Continuous reinforcement occurs when every instance of a designated response is reinforced. In laboratories this method is commonly used to shape and establish a new response before moving on to more realistic schedules involving intermittent reinforcement. Intermittent reinforcement occurs when a designated response is reinforced only some of the time. Intermittent reinforcement makes a response more resistant to extinction than continuous. There are four main intermittent reinforcement schedules. They are: fixed-ratio, variable-ratio, fixed interval, and variable-interval. In a fixed-ratio the reinforcer is given after a fixed number of non-reinforced responses. An example of this would be that it gives reinforcement after (5) responses. A variable- ratio schedule is when the reinforcer is given after a variable number of nonreinforced responses. An example of this would be when a rat is reinforced for every tenth lever press on the average. The exact number of responses required for reinforcement varies from one time to the next. In a fixes interval schedule, the reinforcer is given for the first response that occurs after a fixed time interval has elapsed. An example of this would be students can earn grades by taking exams every three weeks. Lastly, in a variable- interval schedule, the reinforcer is given for the first response after a variable time interval has elapsed. An example is if a person repeatedly dials a busy phone number (getting through is the reinforcer). In each of these different schedules you learn in different ways. It depends on who you are for which one will work best for you.

If a removal of a positive-pleasant stimulus or the addition of a negative/aversive stimulus will lead to an undesired target behavior. Using an intermittent schedule when you are attempting to reduce a behavior may actually lead to strengthening of the behavior; this is certainly an unwanted end result.

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