5 Things You Didn’t Know About Discrete Trial Training (DTT)

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?

Discrete Trial Training (DTT), also referred to as Discrete Trial Intervention (DTI), is a structured method of teaching skills to children that is often misunderstood and misused. Take a look at why you might want to reconsider how you use DTT in your ABA programming.

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1. 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.

Research-Based Interventions

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.

2. 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: Using ABC Data to Make Informed Decisions on Accessible ABA. Take a look at the chart below to see how DTT fits into this framework.

The ABCs as they are used in Discrete Trial Training

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.

The ABCs as they are used in Discrete Trial Training

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.

Take a look at this video of a structured DTT session at the Carbone Clinic. See if you can identify the ABCs in the example.

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: A New Perspective on the Prompt Hierarchy.

3. DTT Does Not 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.

4. DTT Requires a 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:

5. 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!