Choosing the right teaching format directly impacts the success of your clients. Applied Behavior Analysis (ABA) provides a wealth of resources and interventions, so how do you choose the right one?
Two common interventions utilized by professionals include Natural Environment Teaching (NET) and Discrete Trial Training (DTT). While research supports both methodologies, choose carefully based on the needs of your client.
As with any treatment, the strategies discussed here should only be used with the assent of the learner. Read our post Understanding Assent and Assent Withdrawal in ABA for more information on how and why to obtain assent.
Natural Environment Teaching (NET)
NET is a method of instruction that requires careful planning to ensure you capture the targets you identify. Teaching happens throughout the session; however, instruction is less rote than during DTT.
Take a look at this video that includes 4 separate examples of NET.
In each example in the video above, the instructor carefully creates opportunities to teach the identified skill. Sometimes instruction happens on the floor, other times at the table.
Look at the examples from the video
In the first example, the instructor teaches the intraverbal “Ready, set,…” and the preposition “in” and the mand for “ball,” all within the space of 30 seconds. Reinforcement occurs when the instructor gives the child access to the ball for her to use with the ramps. The child’s motivated and engaged.
The instructor in the second example uses the child’s motivation for the vehicles to teach multiple different targets including the intraverbal “what else flies in the sky,” tacting colors, and another intraverbel “something you climb on.” During this session, you see the child make a connection between an item and another person in the room (Elizabeth). These types of connections are critical for more spontaneous learning and are largely unavailable during DTT.
The third example demonstrates NET at a table and you will see the instructor incorporating many different types of targets into the session, all presented in a natural way. The instructor incorporates targets for functional play, tacting animals, and intraverbals such as “what does a cow say?” Other targets include Listener Responding for identifying colors and following simple 1 step directions such as “pour the water.” The instructor uses prompts and prompt fading just as she would if she was using DTT.
The final example shows an instructor working with 2 children. This provides ample opportunities for teaching imaginative play and social skills. The instructor is very intentional in her approach. You see the girl is initially reluctant to follow the instructor’s lead, but the instructor is able to gain her interest and engage her in the activity. The instructor inserts teaching targets into the play throughout the session.
When using NET, the instructors still use error correction and reinforcement to teach a skill. Reinforcement is linked to the activity and driven by what motivates the child.
Discrete Trial Training (DTT)
DTT is a structured form of teaching where the instructor carefully plans the session and controls the conditions. Often this instruction occurs at a table with a high rate of presentation of trials.
DTT utilizes the following format:
Discriminative Stimulus (SD) –> Response –> Consequence
Professionals commonly use Discrete Trial Training (DTT) in treating children with autism, but how well do you understand and utilize this intervention? Children with autism often acquire skills more quickly when therapists and teachers present information in a structured way in an environment free of distractions. DTT provides these features, but are you making the best choice for your client or student?
Follows a Script
Instead of teaching a skill as a whole, this intervention breaks it into discrete steps that are taught independently of each other. The therapist will initiate a quick series of trials without a pause in between. This rapid succession builds momentum and keeps children engaged. Each trial is an attempt to teach the discrete step.
Each trial follows a script with clearly defined steps. This ensures that each trial is exactly the same. For example, if the therapist were teaching a child to identify a dog from a series of pictures he might follow these steps:
- The therapist places a picture of a cat and a picture of a dog on the table.
- The therapist then says “Point to the dog.”
- The child responds by pointing to the picture of the dog.
- The therapist says, “That’s right! Great job!”
- A brief pause before a new trial begins.
The next trial might be:
- The therapist places a picture of a bird and a picture of a dog on the table.
- The therapist then says “Point to the dog.”
- The child responds by pointing to the picture of the dog.
- The therapist says, “That’s right! Way to go!”
- Another pause before a next trial begins.
Trials continue, one after another in quick succession. Often therapists will use prompting to ensure the child provides the correct response.
DTT is Not the Same as Applied Behavior Analysis (ABA)
Parents, teachers and other professionals often use DTT and ABA interchangeably. Some of these individuals resist ABA because they envision the child sitting in a cubicle being drilled to provide rote responses. They believe that ABA leads to producing robots instead of well-educated children. Others feel that this structured approach is the only way a child with severe disabilities can learn and protests if the child doesn’t have access to these structured, distraction-free work sessions.
The reality is that ABA is a methodology that incorporates a wide variety of research-based interventions to change maladaptive behavior and teach new skills. DTT is only one small subset of these interventions that is widely used, but not well understood.
Since the early days of ABA, research has demonstrated the value of the discrete trial method of teaching new skills. There is a significant body of research supporting this intervention for use with children with autism which is why it is often seen as synonymous with ABA. While there’s no doubt DTT produces positive results for many children, other interventions may prove to be more appropriate for a variety of reasons.
Children who learn to learn in a distracting environment expand their chances of success remaining in a general education classroom. There doesn’t appear to be much research supporting this statement; however, I have encountered countless times when children with autism are removed from the general education classroom to provide instruction as they can’t attend to instruction within the classroom. I have also seen situations where children successfully remain in the classroom and attend to instruction (different from that of the classroom teacher). For children with severe social deficits, what situation benefits the child more?
Consider the level of activity in a classroom setting. Will your client or student learn to attend to tasks in a similar environment if you continue with structured DTT sessions? Children who can’t learn or attend to tasks in the chaos of a classroom are removed from their peers and taught in isolation. While this works best for some children, carefully consider if this path works for the children you serve.
Making the Right Intervention Decisions
Incorporate DTT in your programming to teach rote skills if the child needs it, but quickly introduce that skill in more distracting environments. Some children truly struggle to acquire new skills in a distracting environment. For these children, use DTT. In addition, consider whether or not less restrictive programming such as Pivotal Response Treatment (PRT) or Natural Environment Teaching (NET) benefits the child you work with.
Children with autism vary in their needs. As professionals, we must vary our interventions to adapt to each child. Avoid the mistake of routinely including DTT in your programming. Select this intervention only when most appropriate for the children you serve. ABA provides a full array of appropriate interventions. Put them to work for you!
Understanding this confusion helps you better explain programming to parents and other collaterals in the child’s life. You now have the tools to make informed decisions and justify those decisions to influencers in the life of your client or student.
DTT Uses the ABCs of Behavior to Teach Skills
At a very basic level, DTT works because it uses the ABCs of behavior to teach skills. In ABA, the term “ABCs of behavior” refers to the 3-term contingency that is the foundation of how professionals in the field look at behavior. The ABCs stand for:
- Antecedent-what happens right before the behavior you want to understand
- Behavior-the behavior you want to learn more about
- Consequence-what happens immediately after the behavior you want to understand
For more information about the ABCs of behavior, read our post: ABC Data: The Key to Understanding Behavior. Take a look at the chart below to see how DTT fits into this framework.
In the above example, you can see that the antecedent is the discriminative stimulus (SD), the behavior is the child’s response (either correct or incorrect) and the consequence is either reinforcement or error correction. In the example, staff provides the SD “touch your head.” The child responds by touching his head. Staff provide the social and tangible consequence saying “That’s right! You did it! You earned the car!” while giving the car to the child.
The diagram below demonstrates another example. In these examples, notice how DTT fits this 3-term contingency. Below notice that there are 2 different paths dependent on the response of the child.
Intertrial Intervals (ITI) as Part of the Series of Discrete Trials
During DTT, staff typically strive for short Intertrial Intervals (ITI) which essentially means that a series of trials (a sequence of ABCs) is conducted in quick succession without pausing. Staff typically provide quick social reinforcement prior to introducing the next SD. This quick pace often builds momentum, keeps children interested, and builds response speed. After a series of trials (the number determined by the needs of the child), the child typically earns a longer amount of time with a tangible reinforcer.
Error Correction as Part of the Series of Discrete Trials
If you watched the video above, you may have noticed that the child made an error. She responded incorrectly. When this occurs, the instructor conducts an error correction procedure. This procedure is a series that includes:
error –> prompt correct response –> represent trial with same prompt needed to elicit the correct response –> distractor trial –> represent initial trial
Rewatch the video from the Carbone Clinic. Can you see where the therapist uses an error correction procedure? The child actually makes an error during the procedure so the therapist does error correction within error correction. Error correction is your opportunity to teach the child the skill. Don’t skip it!
Children who have no or limited mastered skills may not be successful during this type of error correction procedure. For these children, withhold reinforcement, pause for 5-10 seconds and represent the trial with a more intrusive prompt. For more information on the prompt hierarchy, read our post: Prompt Hierarchy: A New Perspective.
DTT Doesn’t Always Require a Tangible Reinforcer
It’s a common misconception that DTT requires the use of tangible reinforcers. In fact, I recently read an article on Autism Speaks titled What is Discrete Trial Training describing DTT. In that article the author states that tangible reinforcement is a component of DTT. While this is true in many instances, some children find social reinforcers more motivating.
When implementing DTT, the reinforcer you choose directly impacts the success of the intervention. Make sure that you consider what reinforcers are motivating to the child you are programming for. Don’t assume that every child needs a tangible reinforcer.
As professionals, when we provide a tangible reinforcer, we routinely pair some form of social praise with the delivery. We do this so that, over time, the social praise builds value with the eventual plan to fade the tangible aspect of the reinforcer. If we neglect to fade the tangible reinforcer, we do a disservice to the children we serve.
Many children enjoy tickles, hi fives, hugs or a pat on the back. Some enjoy a silly moment or time to jump or engage in stereotypic behavior. Reinforcement is not one-size fits all, and not every child who receives DTT needs or is motivated by tangible reinforcement.
Reinforcer or Preference Assessments
Before you assume that you must provide tangible reinforcement during DTT, conduct a reinforcer or preference assessment to determine what motivates the individual child. Learn more about conducting a reinforcer or preference assessment by reading our post: Reinforcer or Preference Assessment for Children with Autism.
DTT Does Not Need to Take Place at the Table
Traditional formats of DTT involve long hours of children seated in distraction-free work spaces designed to maximize the rate of skill acquisition. Some will argue that DTT requires this component for effectiveness and fidelity. Real life is messy and full of distractions. The children you work with are children first. They experience autism as just part of who they are and this impacts how they learn, but it doesn’t define them.
Allow the children you serve to experience learning in a variety of ways. Encourage learning through play. Sit on the floor with them and engage them. Be fun and reinforcing. Teaching children, especially young children, to be comfortable on the floor may aid their ability to engage more with their peers who spend considerable amounts of time playing on the floor.
Watch this video to see how this therapist implements DTT while on the floor.
In the next video about playing with a child with autism, you can see several opportunities where the DTT sequence of SD –> Response –> Consequence occurs during play. Around the 4 minute mark, you will find the following example:
The SD provided by the child’s grandmother is an intraverbal fill-in commonly used in DTT. The child provides the correct response “Go!” and is offered social reinforcement. Although this looks very different from the video from the Carbone Clinic, many of the components of DTT are the same.
Now that you know more about DTT, use this information to make informed treatment decisions, talk to parents and professionals, and have fun with the children you serve!
Concerns with Discrete Trial Training
One of the primary concerns with DTT is that children learn skills in an unnatural setting. During DTT a child may be able to demonstrate a skill while working with the therapist. However, DTT teaches children to learn in structured environments free of distractions. They might not be able to demonstrate the same skill in a different environment.
If a child can consistently identify a dog when seated at a table with a therapist while there are no distractions, he may not also be able to do this in a classroom with 20 other kids all talking to each other. If your child receives DTT there should be a plan to generalize the skills taught.
Benefits of Discrete Trial Training
Although the concerns about DTT are valid and need to be addressed, this form of therapy has many benefits:
- Children with autism thrive with structure and routine.
- Due to sensory issues, children with autism learn well in an environment free of distractions.
- Skills are broken into discrete components that are easier for children to learn.
- Trials are made up of concrete steps, ideal for children with autism.
- The short trials maximize the child’s chances to complete tasks successfully and provide many opportunities for reinforcement.
But is DTT right for your child?
Is Discrete Trial Training Right for Your Learner?
If your child is part of an ABA program, don’t assume that this has to include DTT. If your child’s therapist includes DTT as one of the interventions, talk to her about why she recommends this form of treatment.
Consider what you know about your child:
- Is she easily distracted?
- Does she struggle to learn rote skills?
- Is she unable to function without rigid structure and routine?
Ultimately it’s your decision if DTT is right for your learner, but be sure the plan includes a way to generalize the skills learned.
Plan For Generalization
A primary concern in ABA is ensuring that trained skills generalize (are observed in novel environments, people or situations). Some believe that skills won’t generalize across settings and people without specific training in that setting or with those people. While it is necessary to ensure you have a plan for generalization, don’t assume that every skill must be taught across all settings and people.
From the beginning of treatment, your main goal of intervention should be to assist the child in improving her ability to generalize without specific training. That being said, the more contrived the situation, the more you need to plan for generalization. For example, the DTT session observed in the above video in the Carbone Clinic is a very unnatural situation for a child.
Most children without autism learn in a group setting, through play or through exploration of their surroundings. When implementing DTT you create a highly controlled and contrived situation that is great for skill acquisition, but not so great for generalization. Ensure before you begin DTT that you have a plan to help the child generalize the skill across conditions.
Take a look at this video about generalization:
Advantages and Disadvantages of NET and DTT
As you can see, there are some distinct differences between the 2 methods
It’s not that one method of teaching is superior to the other. Each teaching method has its own unique advantages and disadvantages. For one client or skill, Natural Environment Teaching might offer the greatest benefits. Another might need the more focused instruction of Discrete Trial Training. Understand the challenges and benefits of each by taking a look at the chart below.
|Natural Environment Teaching (NET)||1. Focuses on the interests of the child|
2. May be easier to motivate the child
3. Easier to program for generalization
4. May be more acceptable to families
|1. Staff must be well-trained to recognize teaching opportunities|
2. Need flexible data collection systems
3. Child may be more distracted
|Discrete Trial Training (DTT)||1. Easier to control distractions|
2. Structure works well for many children and staff
3. Children anticipate reinforcement and perform well
|1. Must plan for generalization|
2. Less natural form of learning for young children
3. May make children appear more “robotic”
When to Choose Natural Environment Teaching
Most children benefit from NET instruction, at least in some capacity. Children with limited play skills or interests struggle more with this type of instruction; however, professionals who carefully plan for this will still find success. If the client you work with is motivated by anything in the natural environment, NET may be a good option for you.
When to Choose Discrete Trial Training
Some children struggle to acquire new skills through NET and require the structured learning environment offered by DTT. These children need a thoughtful plan for generalization of skills learned during DTT. It may be possible to introduce some new targets using NET while also targeting some skills for generalization.
Take a look at this example:
You used DTT to teach tacting colors red, blue and yellow. You plan to generalize this skill by having the child tact colors in the classroom. During this time, you introduce the color green.
Natural Environment Teaching and Discrete Trial Training are not mutually exclusive. You may find it most advantageous to combine the 2 strategies so that your client receives the benefits of both while mitigating the disadvantages.