behavior analysis
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Behavior Analysis. Lecture 10 Maintenance. Review. Last time we talked about generalization training The tendency for the effects of training to spread There are two types of generalization Stimulus generalization and response generalization - PowerPoint PPT PresentationTRANSCRIPT
Lecture 10 Maintenance
Behavior Analysis
Review
Last time we talked about generalization training The tendency for the effects of training to spread
There are two types of generalization Stimulus generalization and response generalization
These two principles refer to behavior generalizing from one situation to another, and from one behavior to another
Today our topic is maintenance, which has to do with getting behavior to generalize from one time to another
In other words, how can we get the changes in behavior to persist over time?
Maintenance
This is sometimes called the maintenance problem.
There are two basic solutions to the maintenance problem, these are: Maintenance schedules Maintenance training
Today we will talk about how to maintain behavior via these procedures
Maintenance schedules
Before we get into the use of maintenance schedules, you need to know about the basic types of reinforcement schedules
A reinforcement schedule is a kind of rule about how reinforcers are to be provided
Schedule of reinforcement: a rule governing the delivery of reinforcers
There are many different kinds of reinforcement schedules, but we will discuss the three main types Ratio schedules Interval schedules Duration schedules
Ratio Schedules
Ratio schedules are based on the number of times the behavior occurs
They are called ratio schedules because the rule for the delivery of a reinforcer specifies ratio of performances of the target behavior to each reinforcement i.e. maybe the target behavior has to occur 3 times
before the reinforcer is delivered
There are two kinds of ratio schedules Fixed Variable
Fixed Ratio Schedule
In a fixed ratio schedule the rule is that the target behavior must occur a certain number of times before it is reinforcedFixed Ratio Schedule: provide a reinforcer after the target
behavior has occurred N number if times If the behavior is on an FR-1 schedule, then the ratio of
target behavior to reinforcement is 1 to 1. i.e. each time the behavior occurs it is reinforced
In fact, this type of schedule, in which the target behavior is always reinforced is called ‘continuous reinforcement’
Schedules that reinforce some occurrences of the target behavior are called ‘intermittent schedules’ For example, with an FR-10 schedule, the behavior has to
happen 10 times before it is reinforced
Variable Ratio Schedule
VR schedules are identical to FR schedules except that the number of instances of behavior required for reinforcement varies around an average
Variable Ratio Schedule: provide a reinforcer after the target behavior has occurred a number of times, with the number varying around an average of n
In a VR-5 schedules, for example, the behavior might be reinforced after occurring 3 times, then after 7 times, then after 2 times, then after 4 times etc
The number of occurrences for reinforcement will change from 1-10, but on average the ration will be 5-1
Interval schedules
In ratio schedules reinforcement is based on the number of times the behavior is performed
In interval schedules, reinforcement is based on the length of the interval between reinforcements.
These schedules are called interval schedules because the rule for the delivery of the reinforcer specifies an interval between reinforcements of the target behavior
There are again two types of interval schedules Fixed Variable
Fixed interval schedule
In fixed interval (FI) schedule, a fixed amount of time must elapse since the last reinforced performance, only then does the behavior qualify for reinforcement again
Fixed interval schedule: provide a reinforcer the first time the target behavior occurs after an interval of N length since the last
reinforcement
For example, if the behavior is on an FI-1 schedule, then after the behavior has been reinforced, a minute must elapse before the behavior will be reinforced again.
Performing the target behavior is not reinforced until the minute has elapsed
Importantly, after the time period has elapsed the behavior has to be performed again before reinforcement is delivered.
Variable interval schedule
VI schedules are identical to fixed interval schedules except the length of the interval between reinforcement varies around an average
Variable Interval Schedule: provide a reinforcer the first time a target behavior occurs after an
interval, with the interval varying around an average of N length
In a VI-5 schedule, the interval might be 2 seconds, 10 seconds, 7 seconds etc but with an average of 5
Duration schedules
Ratio schedules are based on the number of times the target behavior occurs.
Interval schedules are based on the time between reinforcements
Duration schedules are based on how long the behavior must occur without interruption
They are called duration schedules because they specify the duration of the behavior
There are two kinds: Fixed Variable
Fixed duration schedule
In an FD schedule, an activity must be engaged in for a specified period
Fixed duration schedule: provide a reinforcer after the target behavior has been performed
continuously for a period of N length
Fixed duration schedules are very common, a typical example is a child who is required to practice piano for 30 minutes everyday, after which he receives ice cream!
Variable duration schedule
In a VD schedule, the requirement for reinforcement is the same as in an FD schedule except that the period during which the behavior must occur varies around an average
Variable duration schedule: provide a reinforcer after the target behavior has been performed continuously for a period, with the period varying around an average of N
length
For example, the mother may require the her child to practice 10 minutes one day and 50 minutes another day, but the average will be 30 minutes
Maintenance schedules
Ok so we have discussed three kinds of reinforcment schedules: ratio, interval and duration There are others, but these are the main ones
One reason that reinforcement schedules are of interest to us is because of their value in maintaining behavior for long periods
One solution to the maintenance problem is to put the behavior on a maintenance schedule, which is simply:Maintenance schedule: a reinforcement schedule that maintains a target behavior at a desired rate
Maintenance schedules
Much research has been conducted investigating which schedule is ideal at maintaining behavior at high rates with infrequent reinforcement
The ideal maintenance schedule seems to be the variable ratio schedule A reinforcer is provided after the target behavior has
occurred around an average of N
However, when shaping a behavior with continuous reinforcement, it is likely that when you switch to a VR schedule you may get some sort of extinction
Maintenance schedules
Imagine for example, that you gave jonnie a sweetie every time that he finished his math's work (CRF).
When you switch to a VR-5 schedule you may see a drop off in his behavior i.e. he will finish his math's work less.
You may also see increases in emotional behaviorThis has been called ratio strainRatio strain: a reduction in the rate of target behavior
and an increase in emotional behavior resulting from increases in the ratio of behavior to reinforcement
Maintenance schedules
To prevent Ratio Strain you need to avoid abrupt (sudden/sharp) increases in the ratio
Instead, you gradually increase the requirement for reinforcement, this is known as stretching the ratio
Stretching the ratio: gradually increasing the number of times a behavior must be performed to qualify for
reinforcementFor example, with jonnie we wouldn’t move straight
from CRF to VR-10. Instead we would start at VR-1, then maybe VR-2, VR-4 etc.
There is a limit to how much you can stretch the ratio, but you would be surprised at how few reinforcers it takes to maintain target behavior at high rates
Contingency Contracts
So in order to maintain behavior at a high rate, all we have to do is put the behavior on a maintenance schedule. The trouble is that often, people don’t do that.
Once they have produced the desired changes, they stop reinforcing the behavior or they reinforce it so little that the schedule is not rich enough to maintain the behavior For example, imagine you get jonnie to do his work by
giving him sweets. As soon as jonnie starts doing his work, the teacher may stops providing the reinforcers, therefore putting the behavior into extinction
Contingency Contracts
Why? The reason it drops off is because once the changes in the target behavior take place, maintaining that behavior becomes less reinforcing i.e. when the teacher sees jonnie doing his work the use of the
reinforcement schedule is reinforced, but once this increase in target behavior slows down, the use of reinforcement schedule is less reinforced!
In other words, we need make sure that we control the behavior of the person providing the reinforcement
To ensure that they are correctly putting their target onto a maintenance schedule.
You could even say that we need to reinforce the teachers behavior of providing a maintenance schedule, and put that behavior on maintenance schedule itself
Contingency Contracts
We need to find some way of reinforcing the act of maintaining the maintenance schedule
Remember that if a maintenance schedule is to stay in force, the effort required in managing such a schedule must itself be reinforced So were talking about reinforcing the behavior of
the person who’s reinforcing someone’s behavior!That can sometimes be achieved with a contingency
contractContingency Contract: And agreement between two or
more parties about what each is to do for the other
Contingency Contracts
For example, a contingency contract between a teacher and study would specify what the teacher would do that the students find reinforcing, and what the students would do that the teacher finds reinforcing For example, the teacher could want a quiet classroom,
without fooling around and passing of notes. This would give him time to mark papers instead of telling people off
The students could want the freedom to approach the teacher when they find an assignment very difficult and once they had finished the assignment they could have time in the playground
Contingency Contracts
So the teacher and the students must agree on the contingency contract together. If the teacher just makes it up without negotiation then it is not an agreement.
Then someone writes everything down, and all parties sign the contract From the teachers point of view it specifies the target
behavior and the consequences he has to provide to maintain them
From the students view it specifies the teachers target behavior and what they have to do to maintain them
It is therefore a reciprocal relationship
Contingency Contracts
When contract problems arise you deal with it by re-negotiating the terms of the contract
The contract creates a situation in which it is likely that the consequences necessary to maintain target behavior will continue to be provided
This is because if either party breaks the contract then both parties will lose their reinforcers It’s a bit like a job, your employer agrees to pay
you, and you work. If your employer stops paying you, then you stop working
Contingency contracts have been used in many studies and have consistently got positive results
Token Economy
Contingency contracts are great ways to maintain target behavior. A variation of a contingency contract is token economy
A token is something that you can exchange for a reinforcer
The reinforcer that you get for a token is called a back-up reinforcer
Its called that because it is what makes the token valuable; it backs it up
Token Economy: a form of contingency contract, usually involving a group of people, in which the reinforcers are
tokens
Token Economy
There are two defining characteristics of token economies There is a contractual arrangement involving a group
of people Tokens are used as reinforcers, that can at a later
stage be exchanged for back up reinforcers
Most token economies involve students or people in institutions, but the study I am about to describe was set up in the home
Case Study
Wolfe and colleagues devised a simple way to help parents reduce the amount of time their children spent watching TV
They found 3 two parent families whose children, between the ages of 8 and 12, we addicted to TV
The parents had tried the usual things of telling their kids off and reminding them that they should be doing other things, but this did not work
The behaviorists first asked the parents to monitor TV watching behavior over a 7 week period to get a baseline.
This measure showed that kids watched 21 hours per week
Case Study
After this the researchers asked the parents to give their child 20 tokens.
For every 30 minutes of TV watched, the kid had to give up one token
They could not watch TV unless they paid for it in tokens This meant that the kid could watch no more than 10 hours per
week If the kids abided by the rules for 4 consecutive weeks then they
received a reward The results of the study shows that all of the kids reduced their TV
watching behavior to less than 10 hours per week Interestingly, these kids actually spent a little more time doing
homework, and much more time reading. They also reported liking the arrangement and even saved their tokens for special occasions
Social contracts
So you have seen that we can create conditions to maintain behavior.
But society also creates conditions to maintain behavior that’s beneficial to the society
Society tries to maintain high rates of certain behavior and low rates of other behaviors by means of contingency contracts For example, criminal behavior occurs at a relatively
low rate compared to lawful behavior. Of course one reason for this is due to our learning histories.
However, another reason is due to contingency contracts; we have laws that specify that certain behaviors are not allowed and will results in punishment
Social contracts
Social contracts generally go against what we know about human behavior E.g. there is an over emphasis on punishment, and consequences
tend to be delayed and uncertain
Nevertheless social contracts can be used to improve behavior for the better For example, Yokley and colleagues noticed that less and less
parents were getting their children vaccinated against various diseases.
They therefore set up a contingency contract with those parents so that if they had their child vaccinated then they would receive money.
As predicted, those parents were much more likely to have their children vaccinated
What do you think of this?
Social contracts
One lesson that we, as a society, haven't quite learned, is how to make reinforcement contingent on socially desirable behavior
Behavior is not randomThe kinds of behavior we get, depend on the kinds of
consequences that follow itIf we want people to behave differently then we have
to provide different consequences for their behaviorSo we have discussed how to maintain behavior via
maintenance schedules, now we must talk about maintenance training and how that can also help with the maintenance problem!
Maintenance training
The problem with maintenance schedules is that invariably come to a point where they no longer can be maintained For example, the students might move on to a new teacher
It is quite often the case that behavior cannot be put on long term maintenance schedules Imagine the mentally retarded man who improved his
behavior in an institution due to token economy, what happens when he moves to a different care home
As helpful as maintenance schedules are, they seem to be a temporary arrangement
So what can we do to prevent the effects of our training to continue once the intervention is over?
Maintenance training
Maintenance training: intervention procedures that increase the likelihood that changes in the target behavior will persist when the intervention has
ended.In other words, what can we do during the training to make sure that the behavior endures after the training has ended?Imagine you had shaped Billie to be very creative in your classThe following year he may have a teacher that puts creativity into extinction, and reinforce very conventional behavior
Maintenance training
Your intervention needs to make the desired changes resistant to the influences of a less than ideal future.
You may need to immunize Billie against future experiences that may undermine the work you have done in making him more creative
There are 5 maintenance training procedures that help us to do this Continue the intervention well after the target behavior has
been changed Expose the target behavior to its natural reinforcers Teach the person to obtain reinforcement for the target
behavior Shape tolerance for delayed and uncertain reinforcement Fade the intervention program
Continue the intervention well after the target behavior has been changed
ABA seems to get results very quickly It has been recorded that behavior can be made to occur at a
high rate with reinforcement, that shaping has happened in a couple of minutes and that years of a problematic behavior have been reduced by differential reinforcement in dramatic fashion
The problem is that once the behavior has changed for the better, people often assume that that’s the end of it. And there is no need to continue the intervention
They are mistaken, the longer the intervention endures, the longer its affects will last
Therefore the training program should continue ling after the target behavior has occurred, even when the program seems to produce no additional gains
Expose the target behavior to its natural reinforcers
Ultimately, if changes in behavior produced by an intervention are to endure, then the behavior must be maintained by reinforcers it produces in the natural environment
It is therefore important to expose the target behavior to those consequences For example, if a child initially put on her coat
because of reinforcement from her parents, eventually you want to the behavior to come under the control of the natural consequences; the coat keeps her dry and warm.
Teach the person to obtain reinforcement for the target behavior
Sometimes it is possible for the person to increase the availability of reinforcers
One way to do this is to reinforce people who reinforce the behavior For example if Billie’s creative behavior is reinforced
by a sticker, then Billie might reinforce the teachers behavior of getting a sticker, by saying ‘I really like stickers Dr Nic!’
Even more obvious techniques have been used ‘Hey Dr Nic, I've been paying attention, do I get a cookie?’
Shape tolerance for delayed and uncertain reinforcement
Important words for reinforcement are immediate and certain, however in the natural environment, things don’t often work as smoothly
Therefore, if after the intervention ends there is an abrupt shift from immediate and certain to delayed and uncertain, there is likely to be an affect on the behavior
To prevent this the intervention should include a gradual transition from nearly ideal reinforcement to those that resemble contingencies in the natural environment For example, you could gradually increase the interval
between the target behavior and the delivery of reinforcement
Fade the intervention program
At some point the intervention will have to be terminated
In order to maintain the behavior, this should be done gradually For example, imagine someone was trained to live by
themselves in a rehabilitation center. Once the training was done they might first live in a half way house, then an apartment where someone checked on their everyday, then a house where someone checked on them every week.
Fading the intervention program narrows the gap between the intervention environment and the natural environment
Flashcard
schedule of reinforcement a rule governing the delivery of reinforcers
fixed ratio schedule provide a reinforcer after the target has occurred a number
of times
variable ratio schedule provide a reinforcer after the target has occurred a number
of times, with the number varying around an average of N
fixed interval schedule provide a reinforcer the first time the target behavior occurs
after an interval of N length since the last reinforcement
Flashcard
variable interval schedule provide a reinforcer the first time a target behavior
occurs after an interval, with the interval varying around an average of N length
fixed duration schedule provide a reinforcer after the target behavior has
been performed continuously for a period of N length
variable duration schedule provide a reinforcer after the target behavior has
been performed continuously for a period, with the period varying around an of N length
Flashcard
maintenance schedule a reinforcement schedule that maintains a target
behavior as a desired rate
ratio strain a reduction in the rate of target behavior and an
increase In emotional behavior resulting from increases in the ratio of behavior to reinforcement
stretching the ration gradually increasing the number of times a behavior
must be performed to qualify for reinforcement
Flashcard
contingency contract an agreement between 2 or more parties about what
each is to do for the other
token economy a form of contingency contract, usually involving a
group of people, in which the reinforcers are tokens
maintenance training intervention procedures that increase the likelihood
that changes in a target behavior will persist when the intervention is ended