Skill Repertoire Building Procedures

Prompting and Fading

Reviewing DTT (Discrete Trial Training)

DTT is one of the teaching methods that is used to build skill repertoires in ABA programs for children with Autism. The Discrete Trial is composed of three components: The Antecedent (SD or EO) the Response and the Consequence (SR or EC). In order to establish appropriate stimulus control  responses must be reinforced in the presence of the SD (antecedent stimuli or target SDs) that we want to evoke that response.

For example if we want a child to clean up their toys in the presence of the verbal stimuli or target SDs “clean up”, “clean up your toys” or “put your toys away”, than we reinforce cleaning up, the response in the presence of these verbal stimuli or SDs. Over time as a result of this process the child would clean up more frequently in the presence of these SDs. In order to ensure a child’s success in this process it may be necessary to use what we call a prompt.

What is Prompting and Prompt Fading?

A prompt is a stimulus that is presented in addition to the target SD that evokes the target or correct response. In practice, a prompt is a hint, something that we say or do to help the child respond correctly. If the child is not responding in the presence of the target SD on their own, a prompt is added to help the child respond correctly.

For example if a child does not know how to respond to the target SD “sit down” than the therapist presents the target SD “sit down” while at the same time gently guiding the child to sit down in a chair. The child sits and the therapist immediately reinforces the behavior with a consequence.

It is important to be able to establish the difference between a target SD and a prompt. The target SD is the stimulus that we want to evoke the target response, in other words sitting down being the response to the verbal SD “sit down”. A prompt on the other hand is a stimulus that is temporarily required to evoke the target response but it is not the stimulus that we want to ultimately evoke the target response.

In order to make the transition from a prompted response to a response evoked entirely by the target SD the prompt needs to be what we call “faded”. A prompt fading procedure transfers the stimulus control from the prompt to the target SD. Prompt fading involves the systematic removal of the prompt across successive trials so that the stimulus control is transferred successfully from the prompt to the target SD.

Example:

A child is learning to expressively identify objects. The child cannot yet say “car” when they see a car. The target SD is the presentation of the photo of a car and the target response is for the child to say “car”. In order to teach the child this response, initially the therapist will provide a prompt when presenting the SD, in this case the therapist would say the word “car” when presenting the photograph of a car, teaching the child the correct response. The prompt does not stand on its own, the prompt is presented with the SD to help the child respond correctly.  In order for the child to learn correctly on their own without the prompt, the therapist than needs to fade the prompt.  So once the child can respond “car” with a prompt, the therapist would then begin fading the prompt by following fading instructions determined by the BCBA and begin to systematically omit parts of the word car over successive trials to fade this prompt.

Viewing the prompt fading procedure:

Full Prompt: Presenting the target SD with a complete prompt, such as a photograph of a car and the full word, “car”. Initially the prompt alone is evoking the child’s response. Because the goal is to eliminate the prompt, and to have the child respond only to the target SD, the prompt is faded so that the target SD begins to evoke the response.

Partial Prompt: Presenting the target SD with a partial prompt, such as a photograph of a car with the partial word, “ca”. The child responds by saying car and this is immediately followed by an appropriate consequence. This is called a partial prompt because now the therapist need only say a part of the word for the child to respond correctly. Through each successive trial the therapist will omit more of the word as the child’s correct responses continue.

No Prompt: This is the goal of prompt fading. For the child over successive trials to respond solely to the target SD without prompting. At this point stimulus control has been successfully transferred from the prompt to the target SD.

Nine Types of Prompts*:

  1. Physical prompt: A physical prompt is physically guiding the child so that the child can respond correctly. Example: In a therapy session a therapist is teaching a child to respond the the verbal SD “arms up”. In the first instance of teaching this new skill, the therapist says “arms up” and at the same time gently guides the child’s arms up. This is called a full physical prompt because she guided the child through the entire physical action. Through the successive trials the physical prompt faded until no prompt at all was needed for the child to achieve the correct response. During this process the therapist provided consequences for each trial, however the most powerful consequence was provided upon the child successfully completing the target response independently without a prompt to reinforce the independent response. The fading of the prompt transferred stimulus control from the prompt to the target SD.
  2. Model prompt: A model prompt is the therapist demonstrating the target response that the child is expected to imitate. The child must be able to imitate the target response for a model prompt to be used successfully. Example: A therapist is teaching a child to respond to the SD “touch your back”. The therapist presents the target SD and at the same time touches their own back using a model prompt. The child is able to use the demonstration to learn the appropriate response. And like other prompts this prompt to will be faded until the child completes the response independent of the prompt.
  3. Echoic prompt: An echoic prompt is the therapist saying the target response word for word. This allows the child to vocally imitate or echo the correct response.  Example: A therapist is teaching a child to request desired items by color using a full sentence when the child sees the desired item. The therapist holds up the desired item and says, “I want blue”, the child imitates the phrase and receives the item. In the next trial the child then says “green” and the therapist prompts, “I” and the child says, “I want green”. Here the child does not receive the item but instead social praise. Two more trials are conducted with prompt fading and social praise as a consequence and on the fourth trial when the child independently and without a prompt requests the item in a full sentence, receives the item as a stronger reinforcement for the independent behavior.
  4. Directive prompt: A directive prompt is when the therapist tells the child what to do so that they successfully engage in the target response. In order to use a directive prompt the child must be able to independently follow the direction given Example: A therapist is teaching a child to play a game that requires the child to roll a ball back to another person when the ball is rolled to them. In the first trial the therapist rolls the ball to the child and when the child has the ball says the word “push”. The child pushes the ball and it rolls back to the therapist. In each successive trial the direction is decreased until the child independently pushes the ball back to the therapist upon the being rolled to them. As the prompt fades the consequence becomes more powerful.
  5. Textual prompt: When presenting a textual prompt the therapist uses written words to evoke the target response. Example: The child is unable to find and select an item when given a verbal instruction (SD) to do so. To teach the child to respond to the target SD, the therapist presents an array of objects, says the target SD “book” and provides the textual prompt of the word book on a slip of paper. The child selects the book and hands it to the therapist who smiles and provides social praise for the correct response. In the next trial the therapist represents the objects, says “give me the book” and holds up the slip of paper that says book. The child responds correctly. Prompt fading ensues (in each successive trial the word book on the slip of paper becomes smaller and smaller until no writing appears and ultimately no slip is used.)  Likewise, consequence becomes more powerful when the child responds independently to the SD without the prompt.
  6. Gestural prompt: A gestural prompt is the therapist gesturing or moving their body in some way to indicate the target response. Gestural prompts include pointing, touching, tapping and looking as a way to indicate the target response.  Example: A therapist is teaching a child to respond to the target SD “put behind”. The therapist says “put behind” uses a gestural prompt -pointing- to indicate that the child should put the object behind the chair. The child then puts the object behind the chair. The prompt is faded and the consequence becomes more powerful once the child is able to independently and correctly respond to the target SD without a prompt.
  7. Proximity prompt: A proximity prompt is when the therapist uses “position cues” to indicate the target response. In a proximity prompt, the therapist would present an array of object with the target response being placed in closest proximity to the child. Example: A therapist is teaching a child to receptively identify objects. In this example a lemon. Initially the therapist place only the lemon directly in front of the child and leaves the other food item near themselves. Through successive trials the lemon is moved further away until eventually the other item is placed next to the lemon, where the child will then respond independent of the prompt and pick the lemon out of the array regardless of its proximity. So here to the prompt fades and the consequence becomes more powerful when the child responds independently without a prompt.
  8. Voice Inflection prompt: A voice inflection prompt is when a therapist raises or lowers their voice when presenting the target SD to make a particular part of the SD more noticeable, in other words emphasizing. Example: A therapist is asking a child “what is it” and the child confuses the SD with “what color is it”. To assist the child the therapist uses a voice inflection prompt to help them understand what is being asked. The therapist presents the SD “what is it”  when holding up the object to be identified in the initial trial and when the child responds with the color of the object instead, the therapist places emphasis on the question “what is it” in the second trial, where the child then answers the question correctly. In the third trial no prompt is provided and the child answer the question correctly independent of a prompt. Prompt fading is rapid and the consequence is more powerful when the child responds correctly to the target SD without assistance. The therapist then conducts a series of trials switching between the SDs “what is it” and “what color is it” to ensure that the child understands both target responses and can answer each independently.
  9. Stimulus Manipulation prompt: A stimulus manipulation prompt is when a therapist makes changes to task materials to assist the child in responding correctly. The color, size or shape of a specific task material may be changed in order to assist the child in learning. Example: A therapist is teaching a child to receptively identify a circle, the target SD is the presentation of a circle beside another shape while the therapist says, “point to circle”. The target response is for the child to point to the circle. The therapist uses a stimulus manipulation by presenting the circle as a very large shape next to a small square and saying “point to circle”. The child correctly points to the circle. Through each successive trial the therapist fades the prompt by decreasing the size of the circle in each presented SD. As the prompt fades and the child answers correctly and independently to the target SD the consequence once again becomes more powerful.

This listing of prompts is not exhaustive and other types of prompts may become self-evident during a child’s program. These are the most commonly used prompts when teaching new skills.

*Probe Trial: A therapist can probe to find out if a child already knows how to respond to a target SD without a prompt by initiating the discrete trial’s antecedent without a prompt. If the child does not respond the therapist can introduce one of the prompt methods with the SD.

Procedures That Can be Used to Fade a Prompt:

Most to Least Prompting: Most to least prompting is beginning with a prompt that provides the most assistance, and fading to a prompt that provides the least assistance, across trials. When using most to least prompting, a most to least hierarchy will be developed and used, a list of prompts to use that progresses from most to least assistance. It clearly identifies the prompt to begin with and identifies the prompts to fade to as the child is successful until ultimately the child is responding independently and correctly to the target SD without any prompting. This kind of fading can occur within one type of prompt or across different types of prompts. In other words, when fading across types of prompts that could include beginning with a full physical prompt and gradually fading until using a gestural prompt and then again until there is no prompt.

Time Delay: Time delay prompting is the transfer of stimulus control from the prompt to the target SD through increasing the elapsed time between the presentation of the target SD and the prompt across trials. The goal of time delay prompting is ultimately for the child to beat the prompt and respond independently. In essence this means that the therapist presents the target SD with the prompt and then after two successive trials begins to increase the time delay between providing the SD and the prompt allowing the child to respond independently before the prompt is given. The first delay would be one second, and successive successes would result in the delay increasing up to three seconds until the child is able to beat the prompt without error before completely fading the prompt out.

These two fading procedures can be used independently or in conjunction with one another and are used to both teach new skills and correct errors.

How to Use a Prompt to Teach a New Skill:

In teaching a child a new skill that they have not yet mastered, the prompt is presented with the target SD on the first trial and then systematically faded across successive trials. This is called errorless learning. Errorless procedures are used when a child is in the early stages of learning a new skill. The goal of errorless learning are to minimize or eliminate incorrect responses as the child acquires the new skill.

When teaching a new skill, correct responses to prompted SDs are given appropriate consequences (i.e. social praise for assisted correct responses and social praise with more powerful consequences with independent correct responses thereby reinforcing independent correct responses).

How to Use a Prompt to Correct an Error Response:

There are three types of error responses, first when the child responds incorrectly, second when the child takes longer than 3 seconds to respond and finally when the child’s response includes extraneous behavior. The use of prompts are critical to error correction and the error correction procedure.

Three types of error corrections:

  1. Error correction in the early stages of learning a new skill: In this case errorless learning procedures are used when a child is learning a new skill. And while it is rare for a child to make errors when errorless learning procedures are used, the child may engage in errors from time to time as prompts begin to be faded. In the occurrence of an error response, the therapist would respond with a short clear informational “no”, which is given in a neutral tone of voice to inform the child of their incorrect response, and then the therapist would present the target SD again using the last effective prompt in an effort to ensure the correct response and then fade the prompt until the child is able to provide the target response without a prompt over subsequent trials.
  2. Later stages of learning: In later stages of learning either the No, No, Prompt, Repeat or the Least to Effective Prompts will be used for error correction.

No, no, prompt, repeat: The no, no, prompt, repeat procedure is often used when presenting SDs that the child has consistently responded correctly to in the past. In practice an error in the trial would be responded to with an informational “no” with a repeat of the SD in the next trial. If the child responds incorrectly again, an informational “no” is provided, however in the subsequent trial when the SD is presented a prompt is given with the SD, using the last effective prompt that the child gave a correct answer with. When the child responds correctly this time, a mild consequence or reinforcer is used. Once the child is able to again respond correctly to the SD without a prompt the reinforcer or consequence provided will be more powerful.

With previously mastered skills, strong reinforcement or powerful consequences should only be given once the child responds correctly without prompts. And only mildly reinforce the prompted responses.

Least to effective prompts: Least to effective prompts will also be used in later stages of learning error correction. This is most effective when the therapist is uncertain if the child really knows the correct response. For example, a child may have a history of inconsistent responding or a known difficulty with a particular target. In this case the least to effective prompt procedure will be used. In practice the therapist would provide the SD without a prompt in the first trial and an incorrect response would result in an informative “no”. In the second trial the therapist would provide the SD again, however this time they would also use the least intrusive prompt with the SD. If the child still does not respond correctly, in the third trial the therapist would provide the last effective prompt along with the SD. Once the correct response is achieved, the therapist would then begin fading the response until the child is able to answer both independently of the prompt and correctly.

It should be noted that many children respond correctly to the least intrusive prompt and the follow up trial using the last effective prompt is not needed. And in other cases a prompt simply isn’t effective.

What to do When a Prompt is Not Effective in a Given Trial:

If a prompt being used in a particular trial does not evoke the target response, the trial would conclude with an informational “no” and the SD would be repeated with a stronger prompt–a prompt, that is highly likely to evoke the correct response. Such as a fully physical prompt for a nonverbal response or an echoic prompt for a verbal response.

Prompt Guidelines:

  1. Use the least intrusive prompt possible: For example, if just touching a child’s hands is enough to result in the target SD of clapping the therapist should not provide a full physical prompt.
  2. Avoid giving inadvertent prompts: In other words, inadvertent prompts are unintentional behavior on the part of the therapist that evokes the target response in the child (such as the therapist inadvertently directing their gaze at the target SD while presenting the target SD “Touch the car”. The therapist did not intend to prompt the child with there gaze and thereby this is an inadvertent prompt)

The use of effective prompts and prompt fading procedures is critical to establishing appropriate stimulus control and the ultimate success of the child


Shaping

In ABA the core principal states that the consequences that follow a behavior, control whether or not that behavior will increase or decrease. Therefore, target responses or behaviors that are followed by reinforcers will increase in frequency over time. However behaviors that have not occurred cannot be reinforced. If a child does not engage in a particular target behavior at least occasionally the therapist must do something to make the behavior happen.  One way to get a child to engage in the target behavior is through a prompt, however, some target behaviors are not easily prompted and in these cases it may be appropriate to use a procedure called “shaping”.

What is shaping?

Shaping is a behavioral procedure in which one systematically reinforces successive approximations of a target behavior while extinguishing previous approximations. In order to understand this definition one must also understand what is meant by “successive approximations”, and to this end, successive approximations are behaviors that are becoming increasingly more similar to the target behavior.

To reinforce successive approximations of a target behavior the therapist first reinforces an existing behavior that is in the child’s repertoire that is an approximation or similar to the target behavior. Over time, the therapist reinforces behaviors that are closer and closer to the target behavior.

Addressing the last part of the definition of shaping, “extinguishing previous approximations” means that once the child is engaging in a closer approximation to the target behavior the therapist no longer reinforces the less desired previous approximations.

Although most people are unfamiliar with the term “shaping” it is a common occurrence in a child’s life. Children often learn to talk and communicate because these behaviors have been shaped from the time they were infants.

Example: A baby begins to babble. In response to the baby’s babbling the parents repeat the sounds back to the child while smiling and encouraging, ultimately reinforcing the babies cooing and increasing the frequency that the baby engages in the behavior. This is shaping. This cooing will ultimately lead to wordlike sounds and then words and then phrases and then sentences and as the child progresses through the stages of communication previous approximations of correct speech will no longer be reinforced.

When should shaping be used?

Shaping is used when the child is not currently engaging in the target behavior and when the target behavior cannot be easily prompted.

How do you shape a new behavior?

  1. Identify the target behavior. This is the ultimate goal, the behavior expected from the child at the conclusion of the shaping procedure.
  2. Identify the initial behavior to be reinforced. In other words what behavior can the child begin with  (that is already in their repertoire) that is an approximation or similar to the target behavior. This initial behavior is frequently called the first approximation.
  3. Reinforce the initial behavior until it starts to occur consistently.
  4. Raise the criterion for reinforcement to a closer approximation of the target behavior, and no longer reinforce the previous approximation. Once the initial or previous behavior is occurring consistently, raise the bar on expectations and then reinforce the new behavior which resembles closer the desired target behavior. At the same time the previous behavior is no longer reinforced.
  5. Continue the shaping process until the child acquires the target behavior.

Shaping can take time often days or even weeks before the child begins to exhibit the target behavior. To improve the efficiency of the shaping method a prompt may be added.

How can prompting and fading procedures be used to increase the efficiency of shaping?

Example:

A child has just learned to peddle their tricycle, however the child rarely peddles more than a couple feet down the sidewalk. The target behavior is for the child to ride their tricycle from their house down to the corner of the sidewalk. To reach this goal they will shape the distance that the child is required to peddle. The SD in this example is “ride your bike”. The target response is the child riding their tricycle to the corner.

The first approximation: is for the child to ride the tricycle 2 feet down the sidewalk. The BCBA has added two prompts to the shaping procedure to increase efficiency, first a gestural prompt (pointing to the child’s foot which is on the raised peddle) and second a verbal prompt (push). This behavior will be reinforced until it is occurring consistently.

Raise the criterion: once the behavior is occurring consistently the goal will be pushed towards a closer approximation of the target behavior and the previous behavior will no longer be reinforced. Here too, the prompts are still being used. And the consequence increases slightly. However by the end of the session the gestural prompt will be faded completely and only the verbal prompt push will be used.

Raise the criterion again: once again when the behavior is occurring consistently the goal will be pushed towards a closer approximation of the target behavior and the previous behavior will no longer be reinforced. Here the verbal prompt push will be used intermittently. So as the approximations become closer to the target behavior, the prompts will be faded out and the consequences will become more powerful.

Raise the criterion again- The Target Behavior: once again when the behavior is occurring consistently the goal will be the target behavior and the previous behavior will no longer be reinforced. Here all of the prompts will be faded and the child will only receive reinforcement for the target behavior.


Discrimination Training

Discrimination training involves teaching a child to respond to different target SDs or more accurately to discriminate between target SDs.

What is Discrimination Training?

Discrimination training is the process of reinforcing a target response only when the target antecedent or SD is present. There are two things happening in discrimination training. First, the target response is reinforced in the presence of the target SD. And second, when the target response occurs in the presence of an SD other than the target SD, the response is not reinforced. Practically speaking, to discriminate means to tell the difference between, so when conducting discrimination training, the child is learning to tell the difference between two or more SDs.

When is Discrimination Training Used?

Example:

A therapist places a bottle of bubbles and a cookie on a table, and presents the SD “touch bubbles” to the child. The child doesn’t understand what is being asked and picks up the cookie. The therapist then presents the SD “touch cookie”. This time the child picks up the bubbles. If the child continues to respond in this way it indicates that the child cannot tell the difference between the SDs. At this point discrimination training would ensue.

Example:

A therapist presents the SD “sit down” to the child. The child looks at the therapist and then walks away. The therapist once again presents the SD “sit down”. This time, the child turns around. This behavior indicates that the child cannot discriminate the SD “sit down” from other SDs such as “turn around” or “walk away”. Here too, discrimination training would ensue.

Important Definitions:

Acquisition Target or (Target): These terms are used to describe the SD/Response relationship that is currently being taught. The target SD is the presentation of the stimulus or stimuli and the target response is the behavior expected in the presence of the target SD. It is often said that the target SD and response are “on acquisition”. A child may have more than one target on acquisition for any given lesson (i.e., the lesson is to respond correctly to the function of given objects upon being presented the target SD such as “give me the one that colors” or “give me the one you throw”). However, there must always be at least one target on acquisition for each lesson in a child’s program.

On Acquisition: The early stages of learning a new skill. This will be referred to as an SD response relationship that is currently being taught as the current target.

Mastered Target: This term is used to describe SD/Response relationships that the child has already learned or “mastered”. A determination made based upon the criteria set forth in the child’s learning plan by the BCBA.

Distractor Item: Distractor items are additional items that are not targets, used in simultaneous presentation procedures to teach a discrimination. This would be any other item presented to the child that was not part of the target response, for example if the SDs are “give me the object you color with” and “give me the one that you throw” and there was a crayon, a ball, and a spoon presented, the spoon is a distractor. A distractor can be either an item known to the child or unknown.

Distractor Trial: Are additional trials that do not include the acquisition target, used to teach discrimination. A distractor trial may be used in either a simultaneous or successive presentation. It is good to note that in a successive trial there is no distractor item and in this case trials of acquisition target are interspersed with previously learned or mastered targets to teach the child to discriminate. The trials that included previously mastered targets are called distractor trials.

Simultaneous Example:

A distractor trial in a simultaneous discrimination trial is simply the inclusion of a known distractor item. An item the child already knows and has mastered through previous lessons.

Successive Example:

A therapist is teaching a child to respond to the SD “come here”. The therapist provides the SD “come here” along with the gestural prompt of opening his arms and motioning towards themselves. Once the child is completing the target behavior independently and correctly without prompt, the therapist inserts a distractor trial with the already mastered SD “sit down”. A distractor trial must include a mastered target.

Massed Trials: Are the repeated presentation of one SD across consecutive trials. This procedure may be used when first beginning to teach a new skill. In working with children the acronym “MT” will be common and used most to save time and for data collection.

Example:

A therapist is teaching a child to respond to the SD “come here”. The child responds by walking to the therapist. The therapist has been instructed by the BCBA to Mass Target this SD. To do this, the therapist presents the target SD across successive trials. No other SD is used during this time. The number of trials conducted will depend upon the child and the instructions of the BCBA.

Random Rotation: Random rotation or RR in data collection is a procedure that is used to ensure that a child can discriminate between two or more SDs. In practice, RR involves the presentation of two or more SDs in random order.

Example:

A child has already mastered the instructions or target SDs “sit down” and “stand up”, the target SD for the current lesson is “come here”. The therapist will rotate between the two mastered SDs and the new unknown SD, the order of presentation being entirely random.

Mastery: Mastery is an objective method of determining when a child has learned a target. The BCBA will outline mastery criteria for each skill.

Example:

The therapist provides the targets SD “come here”. The child walks to the therapist. The BCBA determines that when the child responds to this SD with 80-100% accuracy when presented in random rotation with other SDs across at least 2 consecutive therapy sessions the target will be considered mastered. The level of accuracy required along with the number of sessions needed will depend upon the child’s individualized plan and the specific target the child is learning.

Types of Discrimination Training and How to Use Them:

Simultaneous Presentation:

Simultaneous presentation is used when a child must respond to a field of stimuli, in other words, when multiple objects are placed in front of the child and that child is then asked to “touch”, “point to” or “pick up” an item. The other items present in the field are called distractor items. When the target and the distractor items are placed simultaneously in the field of stimuli than simultaneous presentation procedures are used to teach the discrimination. Simultaneous presentation is often used in matching lessons where a child is expected to match one item to another, and in receptive labeling lessons where a child is expected to touch or give a specified item.

How to Teach a Discrimination Using  Simultaneous Presentation Procedures:

When using Simultaneous presentation to teach a discrimination there is a 7 step process (referred to as “The 7 Steps” for the first two targets that have been identified by the BCBA. The remaining targets of the lesson will use a 4 step process (referred to as “The 4 Steps for targets beyond the first two). The 7 step process teaches the child to discriminate between the first two targets.

The Seven Steps

Step One: Mass Trial Target 1, Alone | In other words, repeatedly repeating the same SD with no other stimuli. Often during step one a prompt is used and then faded. Step one is complete only when the child is able to respond correctly and independently without a prompt.

Example:

A therapist is teaching a child to receptively identify written words, the lesson is called “sight words” meaning that the child is learning to recognize words by sight. The SD for this lesson is two or more sight words written on index cards followed by the instruction to give the therapist a specific sight word. The target response is for the child to pick up the index card with the specific word on it and hand it to the therapist. In this example the sight word is “after”. To begin, the only stimulus in front of the child is the sight word “after” on the index card and a full physical prompt may be used (such as gently guiding the child’s hand to pick up the index card and hand it to the therapist) which will be faded out upon successive trials to assist the child in responding independently and correctly to the target SD without a prompt.

Step Two: Mass Trial Target 1, with 1-2 unknown distractor items | In the second step, the child needs to select the same item as in step one, however this time the stimuli is not presented alone. The child must select the item from a field that contains 1 or 2 unknown distractor items. The distractor item is an item the child has not yet learned, and is also not a target. In this step, because the target item is being mass trialled the distractor item is not asked for. It is there simply to ensure that the child can respond to the target when there are other items present.

Example:

The child is now able to select the sight word “after” when presented alone. The therapist places two index cards in front of the child, one with the target SD ‘after” and the other with a distractor word and asks the child to “give me after” In this example a full physical prompt will likely not be required and instead a less invasive gestural prompt to help the child identify the correct response. The gestural prompt is quickly faded.  The target response is the child picking up the index card with “after” written on it and handing it to the therapist. (It should be noted that the placement of the index cards on the table should be random for each trial presented so that it can be ensured that the child is responding to the sight word and not its location on the table).

Step Three: Mass Trial Target 2, Alone | Exactly like step one with the only change being the target, for example replacing the sight word “after” with the sight word “use”.

Step Four: Mass Trial Target 2, with 1-2 unknown distractor items | Exactly like step two with the only change being the target, for example replacing the sight word “after” with the sight word “use”. Still requires 1 or 2 unknown distractor items, and a less invasive prompt which is quickly faded out.

Step Five: Mass Trial Target 1, with Target 2 stimulus present | The child can select target 1 or target 2 when presented with a distractor item and the fifth step now presents both targets to the child simultaneously (while also randomizing the position of the index cards on the table) however only target 1 is being mass trialled, target 2 is only in the field of stimuli to help the child differentiate or discriminate between two newly learned targets. At this point in the process no prompts may be needed at all. However if a prompt is needed, it would be systematically faded out across the trial until the child is able to respond correctly and independently to the target SD.

Step Six: Mass Trial Target 2, with Target 1 stimulus present | This is exactly like the previous step except that the target 2 is now the target under mass trial and target 2 is only in the field of stimuli to help the child differentiate.

Step Seven: Randomly Rotate Target 1 and Target 2 | The targets are presented randomly to the child (in other words, no particular order) in addition to their random physical placement on the table itself to ensure that the child is responding to the target SD and not the location of the index card.

How to Tell if the Child Has Successfully Mastered the First 2 Targets:

Typically, the child must be able to respond to both SDs with 80-100% accuracy (this could vary depending upon the child or target and the learning plan as prepared by the BCBA), in random rotation across at least two consecutive therapy sessions.

The Four Steps

Step One: Mass Trial Current Target, Alone | In other words, repeatedly repeating the same SD with no other stimuli. At this point in the learning, a prompt may not be needed, as the child is likely familiar with the process. Step one is complete only when the child is able to respond correctly and independently without a prompt. (Same as Step 1 and 3 in the 7 Step process).

Step Two: Mass Trial Current Target, with 1-2 unknown distractor items | In the second step, the child needs to select the same item as in step one, however this time the stimuli is not presented alone. The child must select the item from a field that contains 1 or 2 unknown distractor items. The distractor item is an item the child has not yet learned, and is also not a target. In this step, because the target item is being mass trialled the distractor item is not asked for. It is there simply to ensure that the child can respond to the target when there are other items present. (Same as Step  2 and 4 in the 7 Step process).

Step Three: Mass Trial Current Target, with 1-2 known distractor items | This is the first time that the target is presented with a known distractor item, or an item already learned and mastered.  Up to this point the child has shown that they are able to select the target item by itself or in a field of unknown distractor items. This step is to ensure that the child can select the target among known distractor item, or that they can differentiate between current and previously mastered targets. Like previous steps, only the current target will be requested. Also, while it is not necessary to change the known distractor within a given trial, it is good to change the known distractor in successive trials.

Step Four: Randomly Rotate Current Target with Previously Mastered Targets | The targets are presented randomly to the child (in other words, no particular order) in addition to their random physical placement on the table itself to ensure that the child is responding to the target SD and not the location of the index card. Each target will be requested in these trials (in no particular order and randomly placed within the array). It is also good to note, that though the therapist isn’t presenting the current target word as the target in each trial, that the current target word is presented randomly throughout the discrete trial.

Successive Presentation:

Successive presentation is used when the target and the distractors cannot be presented simultaneously. For example, a child cannot be asked to “sit down” and “turn around” simultaneously. In this case, the target and the distractor occur across successive trials. The distractors in this case are no longer distractor items presented simultaneously in a field of stimuli, but rather distractor trials which are presented successively. Successive presentation will be used when teaching responses that do not involve a field of stimuli. Successive presentation is often used in following instruction lessons which require a child to respond to specific instructions such as “stand up” or “come here” and in expressive lessons which a child is expected to expressively label an item, answer a question, or respond to a statement.

How to Teach a Discrimination Using  Successive Presentation Procedures:

When using Successive presentation to teach a discrimination there is a 3 step process (referred to as “The 3 Steps” for the first two targets that have been identified by the BCBA. The remaining targets of the lesson will use a 2 step process (referred to as “The 2 Steps for targets beyond the first two). The 3 step process teaches the child to discriminate between the first two targets.

The Three Steps

Step One: Mass Trial Target 1, Alone | In step one the target will repeatedly be presented to the child until the child can respond correctly without a prompt.

Example:

A child is learning to expressively label or “tact” or name various objects. The SD is the presentation of an item followed by the question, “what is it?” The target response is for the child to label the item presented. In presenting the child the object and saying “what is it” the first trial contains a full echoic prompt that is faded out over successive trials.

Step Two: Mass Trial Target 2, Alone | In step two the target will repeatedly be presented to the child until the child can respond correctly without a prompt. (Exactly the same as step one but with the change of target)

Step Three: Randomly Rote Targets 1 and 2 | The targets are presented randomly to the child (in other words, no particular order) to ensure that the child is responding to the target SD and is able to discriminate between targets 1 and 2. The child may or may not need a full or partial echoic prompt or an error correction procedure for one or both targets, and if one is required than that prompt will be rapidly faded over subsequent trials.

How to Tell if the Child Has Successfully Mastered the First 2 Targets:

Typically, the child must be able to respond to both SDs with 80-100% accuracy (this could vary depending upon the child or target and the learning plan as prepared by the BCBA), in random rotation across at least two consecutive therapy sessions.

The Two Steps

Step One: Mass Trial Current Target, Alone | In step one the target will repeatedly be presented to the child until the child can respond correctly without a prompt.

Randomly Rotate Current Target with Two or More Previously Mastered Targets | The targets are presented randomly to the child (in other words, no particular order) to ensure that the child is able to discriminate between the newly learned target and the mastered targets and to further ensure that the child is responding to the targets and not the presentation pattern.

Review:

Variations on Discrimination Training:

Procedural variations that may be applied to discrimination training dependent upon the success of the child when standard procedures are used. If the child fails to acquire the target through the standard method, the BCBA may decide to add steps between mass trials and random rotation. These are called expanded trials and graduated random rotation.

Variations on Discrimination Training are to provide additional, intermediate steps for learners who show difficulty with discriminations when standard procedures are used. There are no specific rules as to which variation will work with any given child and the BCBA will ultimately determine the method based upon the unique needs of the child.

Expanded Trials:

Expanded trials involve systematically increasing the elapsed time between presentations of each Target SD by gradually increasing the number of trials (or in other words systematically inserting distractor trials) of previously mastered targets between trials of the current target or Target SD. For some children it is helpful to use expanded trials before beginning random rotation. During distractor trials the distractors do not have to be from the same lesson as the target, they can be from any previously mastered skill. If the child responds incorrectly to a distractor trial, the child is provided only with an informational “no” and the therapist continues to the next step in the expanded trials procedure. However, if at any point the therapist feels that a previously mastered target is no longer mastered the therapist should consult with the BCBA to determine if it needs to be reintroduced.

Step One: Initially when beginning expanded trials, the therapist inserts 1 distractor trial of a previously mastered target between each trial of the Target SD. This is referred to as Expanded Trials with 1 Distractor Trial and it is abbreviated ET1.

Example:

A child is learning to follow simple instructions. The child has already mastered the SD “clap”. The new target behavior is for the child to knock on the table when given the SD “knock”. The therapist begins the expanded trial by asking the child to “knock”. The child responds by knocking on the table. The therapist then inserts a distractor trials with the known SD “clap” and the child responds by clapping. The therapist than conducts another target SD trial by asking the child to “knock”. In this example the child responds by knocking. However, if the child is experiencing difficulty the therapist can insert another distractor trial with a different mastered target followed by a target trial.

Step Two: Once the child is responding correctly to the target without prompts, the therapist moves on to presenting two distractor trials between each presentation of the target. This is referred to as Expanded Trials with 2 Distractor Trials or ET2.

Step Three: Once the child is responding correctly to the target without prompts, the therapist moves on to presenting three distractor trials between each presentation of the target. This is referred to as Expanded Trials with 3 Distractor Trials or ET3.

Once the child is responding correctly to the target without prompts, the therapist moves on to presenting random rotation.

When to Use Expanded Trials:

Expanded trials can be used with either simultaneous presentation or successive presentation.

Example in Successive Procedure: A child is learning to follow simple instructions the child is on the fourth target in the following instructions lesson. So the therapist would use the shorter 2 step successive presentation process and insert the expanded trial in between step one and step two (in other words after mass trials and before random rotation). It would look like:

Step One: Mass trial current target
    ET1: One distractor trial between each target trial
    ET2: Two distractor trials between each target trial
    ET3: Three distractor trials between each target trial
Step Two: Random rotation presenting the four SDs in random order.

Example in Simultaneous Procedure: A child is learning to receptively identify sight words. The child is on the sixth target. So the therapist would use the shorter 4 step simultaneous procedure and insert the expanded trial in between step one and step two (in other words after mass trials and before random rotation). It would look like:

Step One: Mass trial current target, alone
Step Two: Mass trial current target, with 1 or 2 distractor items
Step Three: Mass trial current target with 1 or more previously mastered targets
     ET1: One distractor trial between each target trial*
     ET2: Two distractor trials between each target trial*
     ET3: Three distractor trials between each target trial*
Step Two: Random rotation of the current target with previously mastered targets.

*Note that the distractor trials can contain mastered content from other lessons, so despite the fact that the child is currently working on receptively identifying words, lessons from sequencing lessons, or functions and prepositions lesson, or other mastered targets can be used during these trials.

Graduated Random Rotation: Graduated random rotation involves systematically introducing mastered targets one at a time, into random rotation procedures.

The steps in Graduated Random Rotation are: First, Random Roation with 1 Previously Mastered Target, than Random rotation with 2 Previously Mastered Targets, and lastly Random Rotation with 3 Previously Mastered Targets

Example:

A child is learning to follow simple instructions the child is currently acquiring the target “knock” and having already mastered the target “clap”. The therapist presents the target SD “knock”, the child responds by knocking. In the next trial the SD “knock” is presented and the child responds correctly. In the third trial the therapist presents the previously mastered target “clap”, and the child responds correctly. Followed by another trial of the current SD “knock” The child was able to respond correctly without prompts to the target SD.

In graduated random rotation, if the child responds incorrectly the therapist implements an error correction procedure using Most-to-Least Prompting,  If the child responds incorrectly again, the therapist will then use the last successful prompt to help the child learn the correct answer.

Example in Successive Procedure:

Step One: Mass trial current target
    RR1: One distractor trial between each target trial
    RR2: Two distractor trials between each target trial
    RR3: Three distractor trials between each target trial
Step Two: Random rotation with the current target and previously mastered targets.

Example in Simultaneous Procedure:

Step One: Mass trial current target, alone
Step Two: Mass trial current target, with 1 or 2 distractor items
Step Three: Mass trial current target with 1 or more previously mastered targets
    RR1: One distractor trial between each target trial
    RR2: Two distractor trials between each target trial
    RR3: Three distractor trials between each target trial
Step Four: Random rotation with the current target and previously mastered targets.

 

The Difference Between Expanded Trial and Graduated Rotation:

Expanded Trials:

  • The order in which SDs are presented is predetermined by the patterns within each step of the ET proceudre.
  • Some children discern patterns easily, and the pattern within expanded trials may initially serve as a prompt.
  • There is no limit to the number of previously mastered targets that can be used in the distractor trials.

Graduated Random Rotation:

  • The order in which SDs are presented are purely random.
  • Previously mastered targets are introduced slowly, only one at a time. (This difference may be important for children who have difficulty going from massed trials to full random rotation, where they have to discriminate between the current target and many mastered targets).

When to Use Most-to-Least Prompting and Error Correction During Discrimination Training:

A most to least prompt should be used during the early stages of learning, however in later stages it is the Error Correction procedure that should be implemented.

Most-to-Least: Most-to-least prompting, should be used when a child’s response is somewhere between 0-79% correct through all steps of the training discrimination procedures from Massed Trials through Random Rotation. When using the standard discrimination training procedures it is common to have completely faded prompts during steps involving mass trials, if so and the child later needs a prompt during random rotation, than the last effective prompt should be used and then faded over successive trials of the target. In addition, if the BCBA has determined that either ET (Expanded Trials) or GRR (Graduated Random Rotation) are to be used, than here too, if a prompt is needed than the last effective prompt should be used and then faded over successive trials.

Error Correction: Error correction procedures such as No, No, Prompt, Repeat should be used in later stages of learning, specifically Least-to-Effective prompts should be used when a child is responding correctly at least 80% of the time or greater during random rotation.


Chaining

Many of the skills that children with Autism need to acquire are complex behaviors that contain multiple single responses, such as playing a board game which may require one to pick up the dice, roll the dice, pick up their game marker, move the marker the number of spaces specified by the dice. In order for a child to take their turn, these responses must occur in a specific sequence.

What is a Behavior Chain?

Complex behaviors comprised of multiple single responses, such as taking a turn playing a board game, are called Behavior Chains. In technical terms, a Behavior Chain is a sequence of SDs and Responses, where each Response in the sequence except the last one produces the SD for the next response in the sequence. In other words Response 1 leads to SD 2, and Response 2 leads to SD 3 and so on. However the last response leads to a reinforcer.

Of course the entire sequence or behavior chain is initiated by an SD. This SD that initiates the first response in the behavior chain is called the Initiating Stimulus or SD.

Example:

Eating cereal. The first SD in this chain is the presence of a bowl of cereal, with the instruction “eat your cereal”. This is the initial SD which evokes the response, picking up the spoon. This response provokes the second SD which is the spoon in the child’s hand which evokes the second response which is the child scooping the cereal with their spoon, which provokes the next SD which is cereal on the spoon which evokes the response putting the spoonful of cereal into the mouth.

In order for a child to engage in a behavior chain independently over time the last response in the behavior chain must be reinforced. In the above example eating the cereal is the reinforcer for this behavior chain. Eating with a spoon is just one of many behavior chains that children with Autism need to learn.

In order for a therapist to teach a behavior chain each individual SD and Response component included in the chain must be identified. To do this a task analysis is performed.

What is Task Analysis?

Task Analysis is the process of breaking down a behavior chain into a sequence of individual SD-Response components. In general, the BCBA will conduct the task analysis and provide instruction to the therapist.

How is a Task Analysis Conducted?

  1. First – Identify all of the responses necessary to perform the behavior chain, and list them in the order in which they should occur.
  2. Second – Identify the SD associated with each response in the behavior chain.
  3. Third – Identify the initiating SD for the behavior chain.
  4. Fourth- Identify the natural reinforcers that maintain the behavior chain in the child’s natural environments

Example: A task analysis of putting on a shirt, so that a child may learn to independently put on a shirt.

Step 1: Identify all of the responses necessary to perform the behavior chain, and list them in the orderin which they should occur.

Response 1: Pick up the shirt
Response 2: Scrunch it from the bottom up to the collar.
Response 3: Lift the shirt over the head and push head through the collar opening.
Response 4: Put arms through the sleeves of the shirt.
Response 5: Pull the shirt down over stomach.

Step 2: Identify the SDs associated with each response in the behavior chain.

SD1: Shirt laying flat on bed
SD2: The child holding the shirt
SD3: Scrunched shirt in hands
SD4: Shirt on over head
SD5: Head and arms in shirt

Step 3: Identify the initiating SD for the behavior chain.

Initiating SD*: Parents want the child to put on a shirt when asked. Therefore the initiating SD is “put on your shirt”

*It is important to note that there are usually many initiating stimulus conditions that naturally occur for a given task. In the example of the shirt, other naturally occurring initiating stimuli might be a) completion of a shower/bath, b) chill felt by the child in the absence of a shirt, c) the desire to go outside, d) conditions that exist when waking up in the morning. Moreover, it is likely that the behavior chain will be taught utilizing each of the naturally occurring initiating stimulus conditions.

Step 4: Identify the natural reinforcers that maintain the behavior chain in the child’s natural environments.

Natural Reinforcers: Being warm, getting to go outside and play.

Every Task Analysis developed is individualized for each child. In other words, the task analysis for brushing teeth will vary between children. The responses and the order in which they occur will be slightly different. Where one child might have 10 steps for brushing their teeth another might have 22.

Once a task analysis has been created, it is time to teach the components of the behavior chain, linking them together in the sequence specified in the task analysis. The strategies used to teach behavior chains are called chaining procedures. Chaining procedures are used to combine two or more simple responses to form a more complex behavior, such as eating with a spoon, putting on a shirt, and brushing teeth as well as putting together a puzzle, speaking in sentences, or playing games. Each of these complex behaviors requires the linking of simple responses together in a specific sequence.

Chaining Procedures:

Forward Chaining:

When using forward chaining the process begins with the initial SD- Response component and then moves forward through the remaining components in the order in which provided in the task analysis.

To teach the child to engage in the first response independently, prompting and fading, shaping, or a combination of the two may be used to help the child learn.

If prompting and fading is the specified method to teach the initial SD than the first trial contains the prompt and is subsequently faded out over remaining trials until the child is responding correctly and independently to the initial SD.

In some cases the lesson will stop once a child completes the first step of the chain. If so, the child would be prompted to engage in the first response to the first SD, provide a reinforcer and then STOP. In other words, no further components of the chain would be taught at this time. In other cases, the entire chain may be taught in every learning trial.

However, in forward chaining the differentiating factor is that the first SD-Response is the focus, and reinforcement is provided to the child contingent upon successfully completing only the first response.

Each new component trial is taught in the same method as the first, with SD2(Stimulus) requiring R2 (Response) in order to provide SR (Reinforcement).

And so on, and so forth.

Example:

A child is being taught how to put on their shirt using the forward chaining procedure. During the Task Analysis it was decided that there were 5 SD-SR components.

Target 1:
SD1: Shirt laying flat on bed & instruction “Put on your shirt”
R1: Pick up the shirt
The initial goal is for the child to perform the first step of the chain independently. So, the therapist conducts a trial for the first step.
Process: The therapist presents SD1 (shirt on bed and vocal “Put your shirt on” with Prompt (pointing) to evoke R1 (the child picking up the shirt –> SR* –> Receives social praise “Good Job!” immediately after responding correctly to the SD. The therapist did not wait to complete the entire behavior chain before providing a reinforcer. Since the target for the trial was the first step in the chain the therapist provided a reinforcer immediately following the completion of the first step of the chain. Additionally, the reinforcer that was provided is not the same reinforcer that would be given following the completion of the behavior chain. That is, the reinforcer that naturally maintains this behavior. Obviously, the natural reinforcer “going out to play” cannot be provided to the child until they are wearing their shirt. So the reinforcers provided during the learning process are contrived reinforcers such as a small piece of food or social praise. They are contrived reinforcers because they do not naturally maintain the desired behavior. For example, parents do not usually follow their children around and give them small pieces of food and social praise for engaging in every step of putting on a shirt. However, in this example the therapist provided a contrived reinforcer when the child completed the first step to strengthen the new behavior. Once the child is engaging independently in this first step the contrived reinforcer will be faded. 

Upon successive trials the therapist will fade the prompt. Once the child is completing this step correctly and independently the therapist can move on to the second step, SD2 if instructed to continue.

Target 2:
SD2: Holding the shirt
R2: Scrunch shirt from bottom up to collar.
Process: Target 2 adds the second step of the behavior chain to the teaching process. The child will now need to perform the first step independently followed by the second step of the chain in order to complete target 2.  Now, after the child picks up the shirt and is holding it in their hands, the therapist prompts the child to scrunch the shirt using a hand-over-hand physical prompt. The therapist immediately reinforces the prompted response with a small piece of food. Then, just as before the therapist continues by performing the rest of the steps in the behavior chain. Across the trials, the therapist fades the prompt from the second step of the chain until the child is able to pick up the shirt and scrunch the shirt independently. Again, the therapist does not wait until the end of the behavior chain to provide reinforcement, since the target is the completion of the first two steps of the chain, the therapist immediately provides the reinforcer following the completion of the second step of the chain. Once again, the reinforcer provided at this point is a contrived reinforcer. Once the child is able to complete the first two steps independently without prompting the therapist moves on to the third target.

Target 3:
SD3: Scrunched shirt in hands

R3: Lift the shirt over the head and push head through the collar opening.
Process: Target 3 raises the requirement again for the child by adding the third step of the behavior chain to the teaching process. Now that the child can pick up the shirt from the bed and scrunch it, the new SD requires the child to lift the shirt over their head and push their head through the collar opening. At this point the therapist prompts the child to put their head through the collar opening using a pointing prompt. The therapist immediately provides social praise as a reinforcer and performs the remaining steps of the behavior chain for the child. Across successive trials of the child putting on their shirt, the therapist fades the prompt for the third response, until the child is able to complete the first three steps independently. 

Once the child can perform the first three steps without prompts the therapist moves to the fourth target.

Target 4:
SD4: Shirt on over head 

R4: Put arms through the sleeves of the shirt.
Process: Target 4 once again raises the requirements for the child. The target response is accomplished in the same way as the previous steps. The therapist begins by presenting the initiating SD, the shirt on the bed and the direction, “put your shirt on” and allows the child to complete the first three steps of the chain independently. The completion of the third response in the chain produces the SD for the fourth target-a shirt on over the child’s head.  Once the child has the shirt on over their head, the therapist physically prompts the child to put their arms through the sleeve holes and immediately provides a reinforcer. The therapist than completes the last step of the behavior chain for the child. Over successive trials of putting the shirt on, the therapist fades the prompt until the child is able to complete the first four steps of the behavior chain independently. 

Finally, now that the chid can independently complete the first four steps of the behavior chain the therapist can move on to the fifth and final target in the chain.

Target 5:
SD5: Head and arms in shirt
R5: Pull the shirt down over stomach.
Process: At this point the therapist waits for the child to complete the first four steps of the behavior chain on their own. As soon as the child has their arms through the sleeves of the shirt, the therapist  prompts the child using a hand over hand full physical prompt to pull their shirt down over their stomach. The therapist immediately reinforces this response with a small piece of food and allowing the child to go outside and play for a few minutes. 

Across successive trials of putting on their shirt the therapist fades the prompt until the child is independently completing the entire chain. For now each time the child successfully completes the chain, the therapist pairs a contrived reinforcer with a naturally occurring reinforcer. Over time, the therapist fades out the contrived reinforcer as the natural reinforcer “going outside to play” maintains the behavior chain of putting on the shirt. The child can perform all five steps of the behavior chain independently with his therapist. Once the child is able to perform the chain for a variety of people, over consecutive days, this chain is considered mastered.

Backward Chaining:

With backward chaining the process begins at the end with the final SD-Response, and then proceeds from end to beginning with each component in reverse order. With backward chaining the BCBA will predetermine how to generate the SD for the first step (which in forward chaining is the last step), which will either be the therapist performing all of the first steps that lead up to the last step, or to create the SD.

Using the “putting on a shirt” example from forward chaining, creating the SD for the final step might be the therapist pulling up the child’s shirt over their tummy so that it above the child’s stomach. In the following example the BCBA has determined that the therapist will perform the first 4 steps in the behavior chain to create the fifth and final S and then begin the backward chaining process

Example:

The child now has their head and arms through the shirt openings and the shirt is pulled up above the child’s stomach, the therapist prompts the child using a hand over hand physical prompt to pull the child’s shirt down over their tummy. The child is reinforced with praise and is then allowed to play outside. Over successive trials, the therapist fades the prompt until the child is responding correctly and independently in the presence of the target SD (which is the shirt over his stomach). Since the child is just learning this behavior the therapist provided a contrived reinforcer in addition to the natural reinforcer upon completion of the last step of the behavior chain.

Since the last step of the behavior chain is followed by the reinforcer that naturally maintains the entire chain the therapist provides the natural reinforcer from the very first learning trial. In other words, with backwards chaining the natural reinforcer can be provided at the conclusion of every learning trial.

This process is exactly like forward chaining with the only difference being the order in which the child learns the lesson. Once the child can perform the entire chain across multiple sessions, correctly and independently the chain is considered mastered.

Total Task Presentation:

In total task presentation, all of the SD-Response components are taught during every learning trial. In other words, the child is prompted through the total task or each step of the behavioral chain on every learning trial. Unlike forward and backward chaining where prompts and contrived reinforcers are systematically faded from one step of the chain at a time prior to moving on to the next target, when using Total Task Presentation prompts and contrived reinforces may be faded for any steps of the chain on each learning trial as appropriate.

With Total Task Presentation, as with forward and backward chaining, the goal is to eventually fade all prompts and contrived reinforcers, so the child performs the entire chain independently.

When teaching a behavior chain using total task presentation, the therapist presents the initiating SD and then prompts the child through every step of the chain with the caveat that the therapist should always use the least intrusive effective prompt. Meaning that if a therapist knows that a child can respond to a gestural prompt versus a full physical response than the therapist should use the gestural prompt. Moreover, each prompt used should be faded as soon as it is no longer needed regardless of the step that is being performed, in other words prompts are not faded in any particular order unlike either forward or backward chaining.

Important to note, is that reinforcement is provided for each step as it is completed independently and correctly and the faded once the child has accomplished this several times and upon independent completion of the behavior chain the chid is provided a natural reinforcer, such as going outside to play. Initially, a contrived reinforcer (such as a piece of food) may be paired with the natural reinforcer (going outside) while the child is learning the behavior chain.

Example:

Target 1:
SD1: Shirt laying flat on bed & instruction “Put on your shirt”
R1: Pick up the shirt
Process: The therapist presents the initiating SD (shirt laying on the bed) and physically guides the child to the bed to pick up the shirt, the therapist provides mild social praise to the child. Immediately the therapist moves to SD2.
SD2: Holding the shirt
R2: Scrunch shirt from bottom up to collar.
Process: With the chid holding the shirt in hands, the therapist physically prompts the child to scrunch the shirt from the bottom to the collar and again provides mild social praise. Immediately the therapist moves to SD3.
SD3: Scrunched shirt in hands
R3: Lift the shirt over the head and push head through the collar opening.
Process: With the child now scrunching the shirt, the therapist uses a full physically prompt to help the child to put their head through the collar opening, providing immediate but mild social praise and moving directly to SD4.
SD4: Shirt on over head 
R4: Put arms through the sleeves of the shirt.
Process: The therapist notices that the child begins to put one of their arms through the sleeve hole independently, and the therapist allows the child to continue to independently complete the action, and provides enthusiastic social praise for putting the one arm through the sleeve, from here there child stops and the therapist physically prompts the child to put their other arm through the remaining sleeve. From here, the therapists sees that the child is independently responding to the next SD already…
SD5: Head and arms in shirt
R5: Pull the shirt down over stomach.
Process: The therapist allows the child to complete the R5 (pulling the shirt down over their stomach) independently. Immediate reinforcement is provided by way of a contrived reinforcer (food treat) and natural reinforcer (going outside to play) because the child completed the entire chain.

 

Chaining Review

Each of the three chaining procedures, forward, backward and total task presentation have similarities as well as noted differences.

Similarities:

Which Chaining Procedures to Use:

Many of the skills that children with Autism need to learn are behavior chains, that is they are complex behaviors that consist of two or more single responses that must occur in a specific sequence. The acquisition of these behavior chains is crucial to the child’s success in his or her home, school and community environments. It is important that the therapist is able to accurately implement the chaining procedures, so that the many behavior chains can be effectively taught for each child’s future success.

Learn More…

Behavior Management: Assessment & Intervention