Lecture5 increasing THE FREQUENCY OF BEHAVIOR – Shaping and chaining Behavior Analysis Lecture5 increasing THE FREQUENCY OF BEHAVIOR – Shaping and chaining

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 pounds If 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 powerful The 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 reinforcment of successive elements of a behavior chain 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 school Once 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 Behavior chain Chaining Forward chaining The reinforcment of successive approximations of a target behavior Behavior 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 chain Forward 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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