ESL Supplemental - Theories (B.F. Skinner)

Schedules of Reinforcement

(A) Continuous Reinforcement: An animal/human is positively reinforced every time a specific behaviour occurs, e.g. every time a lever is pressed a pellet is delivered and then food delivery is shut off. Response rate is SLOW Extinction rate is FAST (B) Fixed Ratio Reinforcement: Behavior is reinforced only after the behavior occurs a specified number of times. E.g. one reinforcement is given after every so many correct responses, e.g. after every 5th response. For example a child receives a star for every five words spelt correctly. Response rate is FAST Extinction rate is MEDIUM (C) Fixed Interval Reinforcement: One reinforcement is given after a fixed time interval providing at least one correct response has been made. An example is being paid by the hour. Another example would be every 15 minutes (half hour, hour, etc.) a pellet is delivered (providing at least one lever press has been made) then food delivery is shut off. Response rate is MEDIUM Extinction rate is MEDIUM (D) Variable Ratio Reinforcement: Behavior is reinforced after an unpredictable number of times. For examples gambling or fishing. Response rate is FAST Extinction rate is SLOW (very hard to extinguish because of unpredictability) (E) Variable Interval Reinforcement: Providing one correct response has been made, reinforcement is given after an unpredictable amount of time has passed, e.g. on average every 5 minutes. An example is a self-employed person being paid at unpredictable times. Response rate is FAST Extinction rate is SLOW

Two Types of Reinforcers

1. Positive Reinforcement: Presenting the subject with something that it likes. E.g. Skinner rewarded his rats with food pellets. More on Positive Reinforcement Positive reinforcement strengthens a behavior by providing a consequence an individual finds rewarding. For example, if your teacher gives you £5 each time you complete your homework (i.e. a reward) you will be more likely to repeat this behavior in the future, thus strengthening the behavior of completing your homework. 2. Negative Reinforcement: Reward - in the sense of removing or avoiding some aversive (painful) stimulus. E.g. Skinner's rats learned to press the lever in order to switch off the electric current in the cage. More on Negative Reinforcement The removal of an unpleasant reinforcer can also strengthen behavior. This is known as negative reinforcement because it is the removal of an adverse stimulus which is 'rewarding' to the animal or person. Negative reinforcement strengthens behavior because it stops or removes an unpleasant experience. For example, if you do not complete your homework, you give your teacher £5. You will complete your homework to avoid paying £5, thus strengthening the behavior of completing your homework.

Behavior Shaping

A further important contribution made by Skinner (1951) is the notion of behaviour shaping through successive approximation. Skinner argues that the principles of operant conditioning can be used to produce extremely complex behaviour if rewards and punishments are delivered in such a way as to encourage move an organism closer and closer to the desired behaviour each time. In order to do this, the conditions (or contingencies) required to receive the reward should shift each time the organism moves a step closer to the desired behaviour. According to Skinner, most animal and human behaviour (including language) can be explained as a product of this type of successive approximation.

Behavior Modification

Behavior modification is a set of therapies / techniques based on operant conditioning (Skinner, 1938, 1953). The main principle comprises changing environmental events that are related to a person's behavior. For example, the reinforcement of desired behaviors and ignoring or punishing undesired ones. This is not as simple as it sounds — always reinforcing desired behavior, for example, is basically bribery. There are different types of positive reinforcements. Primary reinforcement is when a reward strengths a behavior by itself. Secondary reinforcement is when something strengthens a behavior because it leads to a primary reinforcer. Examples of behavior modification therapy include token economy and behavior shaping

Punishment

Imposing an aversive or painful stimulus. E.g. Skinner's rats were given electric shocks. More on Punishment Punishment is defined as the opposite of reinforcement since it is designed to weaken or eliminate a response rather than increase it. It is an aversive event that decreases the behavior that it follows Like reinforcement, punishment can work either by directly applying an unpleasant stimulus like a shock after a response or by removing a potentially rewarding stimulus, for instance, deducting someone's pocket money to punish undesirable behavior.

Educational Applications

In the conventional learning situation operant conditioning applies largely to issues of class and student management, rather than to learning content. It is very relevant to shaping skill performance. A simple way to shape behavior is to provide feedback on learner performance, e.g. compliments, approval, encouragement, and affirmation. A variable-ratio produces the highest response rate for students learning a new task, whereby initially reinforcement (e.g. praise) occurs at frequent intervals, and as the performance improves reinforcement occurs less frequently, until eventually only exceptional outcomes are reinforced. For example, if a teacher wanted to encourage students to answer questions in class they should praise them for every attempt (regardless of whether their answer is correct). Gradually the teacher will only praise the students when their answer is correct, and over time only exceptional answers will be praised. Unwanted behaviors, such as tardiness and dominating class discussion can be extinguished through being ignored by the teacher (rather than being reinforced by having attention drawn to them). Knowledge of success is also important as it motivates future learning. However it is important to vary the type of reinforcement given, so that the behavior is maintained. This is not an easy task, as the teacher may appear insincere if he/she thinks too much about the way to behave.

Introduction to Operant Conditioning

Operant Conditioning deals with operants - intentional actions that have an effect on the surrounding environment. Skinner set out to identify the processes which made certain operant behaviours more or less likely to occur.

Primary and Secondary Reinforcers

Primary Reinforcers: These are stimuli which are naturally reinforcing because they directly satisfy a need. E.g. food, water. Secondary Reinforcers: These are stimuli, which are reinforcing through their association with a primary reinforcer. I.e. they do not directly satisfy a need but may be the means to do so. E.g. Money! You cannot eat it or drink it but if you have it you can buy whatever you want. So a secondary reinforcer can be just as powerful a motivator as a primary reinforcer.

Operant Conditioning & Reinforcement

Reinforcement. Behavior which is reinforced tends to be repeated (i.e. strengthened); behavior which is not reinforced tends to die out-or be extinguished (i.e. weakened). More on Operant Conditioning and Reinforcement B.F. Skinner (1938) coined the term operant conditioning; it means roughly changing of behavior by the use of reinforcement which is given after the desired response.

Three Types of responses or Operants

Skinner identified three types of responses or operant that can follow behavior. 1. Neutral operants: responses from the environment that neither increase nor decrease the probability of a behavior being repeated. 2. Reinforcers: Responses from the environment that increase the probability of a behavior being repeated. Reinforcers can be either positive or negative. 3. Punishers: Responses from the environment that decrease the likelihood of a behavior being repeated. Punishment weakens behavior.

Token Economy

Token economy is a system in which targeted behaviors are reinforced with tokens (secondary reinforcers) and later exchanged for rewards (primary reinforcers). Tokens can be in the form of fake money, buttons, poker chips, stickers, etc. While the rewards can range anywhere from snacks to privileges or activities. Token economy has been found to be very effective in managing psychiatric patients. However, the patients can become over reliant on the tokens, making it difficult for them to adjust to society once they leave prisons, hospital etc. Teachers also use token economy at primary school by giving young children stickers to reward good behavior.