Lecture5 increasing THE FREQUENCY OF BEHAVIOR –

Shaping and chaining

Behavior Analysis

Shaping

Imagine your partner has ill health and has been advised, by the doctor, to swim as much as possible. Except she never swims! If she never swims, then you cant reinforce the behavior of

swimming. And all the prompts you have tried haven't worked, what do

you do?In this situation you will want to reinforce

behavior that takes her in the right direction In other words, you start with what the person does and

build on that toward the behavior you want.This process is called ‘shaping’Lets play a game – hotter and colder

Shaping Defined

Shaping is used when the target behavior does not yet exist

In shaping, what is reinforced is some approximation of the behavior

By approximation, I mean any behavior that resembles the desired behavior or takes the person closer to the desired behavior

Shaping: the reinforcement of successive approximations of target behavior

Successive approximations are steps toward the target behavior, the behavior you want to shape

Shaping

For example, in hot and cold we reinforced movements that takes the player closer to the prize Each step that gets the person closer to the desired

behavior is a successive approximation of that behavior

You can think of the shaping process as a matter of reinforcing a series of sequential steps towards the target behavior We reinforce those steps along the way, not because we

want to establish those steps, but because by reinforcing those steps the person is then more likely to perform the next step and get closer to the desired behavior

Studies (Rickard & Mundy, 1965)

These researchers used shaping to treat stuttering in a 9 year old boy named Steve.

Steve had been in speech therapy for 5 years and stuttered very badly

The researchers defined the target problem as repetition errors in conversational speech

The goal was to reduce the frequency of those errors

This was to be accomplished by reinforcing stutter free speech

Studies (Rickard & Mundy, 1965)

At first, Steve had to read short phrases printed on cards

The researchers provided positive feedback whenever he read without errors, but later supplemented this reinforcement with ice cream

The reinforcers were contingent on a certain standard of performance, with the standards slowly increasing as Steve progressed

Next this procedure was repeated with full sentences and then paragraphs

Studies (Rickard & Mundy, 1965)

However, reading is not the same thing as talking So once Steve could read without repetition errors the

researchers tried conversation

The results of the study showed that Steve was much improved in reading exercises, and that his conversational skills had also improved. His amount of repetition errors had diminished

This study made good use of shaping – It aimed to reduce repetition errors in free speech. In order to get there it used a number of successive approximations: words, sentences, paragraphs, conversation.

Studies (Lovaas, no date)

Chuck was a psychotic child who had many problems

The researchers wanted Chuck to imitate words spoken by adults

In order to do this they shaped his behavior in the following steps Make a sound when the trainer made a sound Make the same sound the trainer made Imitate words

After 26 days of training Chuck was imitating new words and phrases with ease

Studies (Ayllon, 1963)

Ayllon (1963) used a kind of shaping in the treatment of a schizophrenic woman, lets call her Matilda

Matilda liked to wear clothes, lot of clothes! She would wear 6 or 7 dresses at the same time and 18 pairs of socks!

In order to get a baseline measure of how much clothing Matilda was wearing, researchers asked nurses to weigh her everyday for 2 weeks and then take away her actual body weight

Baseline showed that she on average wore 25 pounds worth of clothing

The goal was to reduce this amount

Studies (Ayllon, 1963)

Ayllon (1963) decided that food could be used as a reinforcer

So he made access to the dining hall contingent on meeting a certain weight requirement.

At first she was given a target of 23 poundsIf she weighed more than the target then she

could remove a few items and gain entry, if she didn’t remove clothes she was allowed to eat!

Matilda loved food! So as the target was lowered so Matilda would remove more items of clothing

Eventually Matilda’s clothing weight had fallen from 25 pounds to 3 pounds

Rules for shaping

The studies described give an idea about what shaping is

If used properly then it can be powerfulThe rules for shaping are

Define the target behavior Reinforce successive approximations of the target

behavior Monitor the results

1. Define the target behavior

When shaping is involved, some people refer to the target behavior as the terminal or goal behavior

In order to define the target behavior you have to answer the following question What is it you want the person to be doing at the end

of the shaping procedure?

2. Reinforce successive approximations of the target behavior

Something the person currently does can be said to resemble the target behavior

You shape up the target behavior by reinforcing the nearest approximations of that behavior

When you have reinforced the nearest approximation of the target behavior, other approximations of the behavior will usually appear

Shaping is rather like helping someone up a stair case, each step up the ladder is reinforced.

3. Monitor the results

The only way you can gauge how successful you are being at shaping behavior is by noting what changes in behavior are occurring Are you seeing progress toward the target behavior? Has the behavior broken down?

Is progress too slow? If progress is slow then it is probably because your

steps between approximations are too large The most common mistake with shaping: failing to

reinforce a new approximation that is only slightly better than the last reinforced approximations

Chaining defined

Many new behaviors that you want to build are a series, or chain of behaviors.

A behavior chain is a series of related behaviors that produce reinforcement

Behavior chain: A sequence of related behaviors, each of which provides the cue for the next, and

the last of which produces a reinforcer

Actually, almost everything we do can be considered as part of a behavior chain i.e. even tying your shoes is comprised of series of separate

acts that each is linked to the previous act

Chaining

Each step in a behavior chain serves as cue for the next step

You could even think of a behavior chain as series of signals and behaviors

The completion of one behavior in a chain produces the signal for the next action

Practically any complex behavior you can think of can be thought of as a behavior chain.

So it is pretty important

Chaining

The procedure for building chains is also important, this is called chaining

Chaining: the reinforcment of successive elements of a behavior chain

For example, If you are attempting to teach someone to tie their shoes, you are attempting to build a chain by reinforcing the different acts that we complete in tying a shoe

Forward chaining

There are two chaining procedures; forward and backward.

As the name implies, forward chaining starts at the beginning and moves forward

Forward chaining; a training procedure that begins with the first element in the chain and progresses to the last

element.

So you start with the first task in the chain, once the person is able to perform that element satisfactorily, you have him perform the first and second elements

Once the first 2 elements are competently done, you have the person perform the first three elements, and so on!

Backward chaining

Backward chaining starts with the last component and works backwards

Backward chaining: a chaining procedure that begins with the last element in the chain and

progresses to the first element

Although counterintuitive, backward chaining is often more effective than forward chaining

Studies (Gruber et al, 1979)

These researchers were trying to get Howard, a severely retarded adult man, to work to a school on an institutionalized site

Howard had an IQ of between 8 and 14, and when given the instruction to go school, often wandered off the route.

In order to train Howard how to walk to school the researchers used a chaining procedure

Studies (Gruber et al, 1979)

Beginning near the school, the trainer told Howard to go to school. The trainer would instruct and nudge Howard if necessary. Howard was praised enthusiastically when he got to the

schoolOnce this had been repeated on three

consecutive trials, the researchers started the procedure from 50 yards further away, and so on.

Eventually Howard was able to walk from his living quarters to the school without assistance He did this is 10 days with 17 training sessions

What sort of conditioning is this an example of?

Rules of chaining

The rules for chaining are very similar to those for shaping Define the target behavior Reinforce successive elements of of the chain Monitor the results

1. Define the target behavior

You of course need to know what the end target behavior is

But with chaining, in order to teach someone to perform the links of a chain, you will need to know exactly what those links are

Sometime these chains are obvious E.g. washing our hands

However sometimes they are much more complicated. For example, training someone with a head injury to wash their hands might be more difficult, and you may need to break down the chains into further chains

2. Reinforce successive elements of the chain

Once you know the elements of a chain then those elements in a behavior chain must be reinforced, in sequence

Of course in order to get the first element to appear you may have to shape their behavior! In some cases each link in the chain will have to be shaped up.

3. Monitor the results

Why?

Shaping versus chaining

Many authors suggest that chaining is simply a form of shaping. But it may be worth distinguishing the two.

The crucial similarity between shaping and chaining is that the goal in each case is to establish a target behavior that doesn’t yet occur. For example, if you want someone to read, you cant

just wait for reading to occur, you have to do something to make it occur

Shaping versus chaining

There are several differences between the two procedures Shaping always moves forward. You may have to

return to a previous step, but you will always be looking to move forward. Where as it is quite possible to move backward with backward chaining

Another difference involves when reinforcers are delivered. In shaping, each new approximation is reinforced. In chaining, reinforcers are usually provided at the end of the chain

Flash card!

Shaping The reinforcment of successive approximations of a target

behaviorBehavior chain

Sequence of related behaviours, each of which provides the cue for the next, and the last of which produces a reinforcer

Chaining The reinforcement of successive elements of a behavior

chainForward chaining

Chaining procedure that begins with the last element in the chain and progresses to the first element

Backward chaining a chaining procedure that begins with the last element in

the chain and progresses to the first element

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