When a systematic attempt is made to change individuals‟ behaviour by directing their learning in graduated steps, it is called shaping behavior. There are four methods of Shaping Behavior. They are as follows:
1. Positive reinforcement – This is the process of getting something pleasant as a consequence of a desired behavior, to strengthen the same behavior. For example, one get a commission, if he/she achieves sales target.
i) Bonuses paid at the end of a successful business year are an example of positive reinforcement.
ii) Employees will work hard for a raise or a promotion.
iii) Salesmen will increase their efforts to get rewards and bonuses.
iv) Students will study to get good grades, and
v) In these examples, the rises, promotions, awards, bonuses, good grades, are positive reinforces.
2. Negative reinforcement – This is the process of having a reward taken away as a consequence of a undesired behavior. For example, scholarship is withdrawn from the student who has not done well on the examination. Just as people engage in behaviours in order to get positive reinforces, they also engage in behaviours to avoid or escape unpleasant conditions. Terminating an unpleasant stimulus in order to strengthen or increase the probability of a response is called negative reinforcement.
3. Punishment is causing an unpleasant condition in an attempt to eliminate an undesirable behavior. This is the process of getting a punishment as a consequence of a behavior.
According to B. F. Skinner, punishment is still the most common technique of behaviour control in today's life. When a child misbehaves, he is spanked. If a person does not behave as the society or law wants him to do, he is punished by arrest and jail.
Example: Loss of pay for coming late to office. Punishment can be accomplished either by adding an unpleasant stimulus or removing a pleasant stimulus. The added unpleasant stimulus might take the form of criticism, a scolding, a disapproving look, a fine, or a prison sentence. The removal of a pleasant stimulus might consist of withholding affection and attention, suspending a driver's license, or taking away a privilege such as watching television.
Accordingly, in situations where punishment is desirable as a means of behaviour modification, certain guidelines would make it more effective thus minimizing its dysfunctional consequences.
a) Praise in public; punish in private.
b) Apply punishment before the undesirable behaviour has been strongly reinforced. Thus, the punishment should immediately follow the undesirable behaviour.
c) The punishment should focus on the behaviour and not on the person.
4. Extinction – An alternative to punishing undesirable behaviour is extension – the attempt to weaken behaviour by attaching no consequences (either positive or negative) to it. It is equivalent to ignoring the behaviour. The rationale for using extinction is that a behaviour not followed by any consequence is weakened. However, some patience and time may be needed for it to be effective.
This type of reinforcement is applied to reduce undesirable behaviour, especially when such behaviours were previously rewarded. This means that if rewards were removed from behaviours that were previously reinforced, then such behaviours would become less frequent and eventually die out. For example, if a student in the class is highly mischievous and disturbs the class, he is probably asking for attention. If the attention is given to him, he will continue to exhibit that behaviour. Both positive and negative reinforcement result in learning. They strengthen a response and increase the probability of repetition. Both punishment and extinction weaken behavior and tend to decrease its subsequent frequency.
Schedules of reinforcement
The two major types of reinforcement schedules are continuous and intermittent.
1. Continuous reinforcement schedule: It reinforces the desired behavior each and every time it is demonstrated. It is the traditional reinforcement schedule and is called a continuous reinforcement schedule. Each time the correct behavior is performed it gets reinforced. When there is a 1:1 relationship between the occurrence of a key response and a rewarding result, the schedule of reinforcement is said to be continuous. For E.g. When a new employee joins the organization the boss/senior may praise the employee every time he /she is able to do the assigned task successfully. The main aim behind such action by the boss is to reinforce the right action of the new employee.
2. Intermittent reinforcement schedule: There are fixed and variable categories. In an intermittent schedule, not every instance of the desirable behavior is reinforced, but reinforcement is given often enough to make the behavior worth repeating. The intermittent, or varied, form of reinforcement tends to promote more resistance to extinction than does the continuous form.
Intermittent techniques are placed into following categories:
Ø Fixed-interval reinforcement schedule – rewards are spaced at uniform time intervals; the critical variable is time, and it is held constant. In a fixed-ratio schedule, after a fixed or constant number of responses are given, a reward is initiated. For example, honesty pay is fixed interval reinforcement, and piece rate is fixed ratio reinforcement scheme.
Ø Variable-interval reinforcements – rewards are distributed in time so that reinforcements are unpredictable. When the reward varies relative to the behavior of the individual, he or she is said to be reinforced on a variable-ratio schedule. In general, variable schedules tend to lead to higher performance than fixed schedules. Continuous reinforcement schedules may lead to early satisfaction and behavior may weaken when reinforcers are withdrawn. Continuous reinforcers, thus, are appropriate for newly desired, unstable, or low-frequency responses. Intermittent reinforcers do not follow every response and thus, they also may lead to early satisfaction. They are appropriate for stable or high-frequency responses. Variable-interval schedules generate high rates of response and more stable and consistent behavior because of a high correlation between performance and reward.