the process of making a behaviour more likely to be repeated in the future because it is followed by a pleasant consequence for the learner.
a reinforcer is any stimulus that strengthens a response
In Skinner's experiments, reinforcement occurred when the rat's lever-pressing response was strengthened due to it being followed by the delivery of food.
Skinner distinguished between two types of reinforcement:
Positive reinforcement: the strengthening of a behaviour because it is followed by the addition of a pleasant stimulus. Example: the food being delivered to the rat in the Skinner box, receiving a good grade on a test after several hours of studying
Negative reinforcement: the strengthening of a behaviour because it is followed by the removal of an unpleasant or aversive stimulus. Example: Skinner delivering a mild electric shock to the rat's feet as it moved around the chamber but stopping the shock for a brief period of time each time the rat pressed the lever, taking a paracetamol to relieve a headache
A punisher is any stimulus that weakens a response.
Punishment can refer to:
Punishment (Positive punishment): the process through which a response is weakened when it is followed by the delivery of an aversive (unpleasant) stimulus.
Response cost (negative punishment): the process through which a response is weakened when it is followed by the removal of a satisfying (pleasant) consequence.
Skinner demonstrated how each of these processed worked in the Skinner box after he had conditioned the rats to press the lever.
Example for positive punishment: When the punishment trials began, instead of receiving food for a lever press, the ration received a mild electric shock. Gradually, the lever pressing became less and less likely over time. Everyday example: a parent increasing the chores their child must complete for a week each time the child obtains poor grades.
Example for response cost: the rat could also be conditioned to avoid pressing the lever via the removal of the food for a period of time following each lever press. Everyday example: a parent withholding pocket money for a week when their child obtains poor grades
schedules of reinforcement
a schedule or reinforcement is a pattern of delivering partial reinforcement in operant conditioning trials, where the frequency of the delivery changes according to the type of pattern.
In Skinner's experiments, food was delivered every the rat pressed the lever. This is known as continuous reinforcement.
Continuous reinforcement: reinforcement that follows every response it is intended to strengthen.
Skinner also conducted experiments in which only some responses were reinforced, a process known as partial reinforcement.
Partial reinforcement: reinforcement that follows only some of the responses it is intended to strengthen.
Skinner varied how often reinforcement occurred in order to see the impact this would have on how quickly the learning would take place, and how long the behaviour would continue once learned. These findings are important as it may not be possible or desirable to reinforce every single response, such as when teaching a dog to sit. Skinner identified four different variations of providing partial reinforcement, known as schedules of reinforcement.
schedules of reinforcement - fixed ratio schedule
reinforcement occurs after a specified number of trials have taken place.
Example: a café offering a free coffee for every 5 coffees purchased.
schedules of reinforcement - variable ratio schedule
reinforcement occurs after a changing and unpredictable number of trials have taken place, but on average after a specified number of trials. Example: a parent occasionally adds $5 to their child's weekly pocket money for completing their chores without complaint
schedules of reinforcement - fixed interval schedule
reinforcement occurs for the first response after a specified amount of time has passed.
Example: a real estate agent makes an inspection every 6 months to monitor how a rental property is being kept by the tenants.
schedules of reinforcement - variable interval schedule
reinforcement occurs for the first response after a changing and unpredictable amount of time had passed, but on average after a specified amount of time has passed.
Example: surprise visits from a health and safety inspector to check the cleanliness of a restaurant
Factors influencing the effectiveness of reinforcement and punishment
- Order of presentation: It is important that consequence follows behaviour, so that there is an association between the behaviour and the consequence.
- Timing: the consequence that follows a behaviour is best presented immediately after the behaviour is demonstrated. If there is a delay, then the learner may not make the association between its behaviour and the consequence.
- Appropriateness of the reinforcer of punisher: the stimulus intended to act as reinforcement or punishment for the learner must be suitable for the learner