DTT in ABA

What is Discrete Trial Teaching?

There is an increasing number of children who are diagnosed with autism, and Discrete Trial Teaching (DTT) is an important component of the interventions that doctors, therapists, and educators use with them. It is an important methodology that addresses the way these children learn new skills. What is DTT and how does it help children on the autism spectrum learn?

The Purpose of DTT 

Discrete Trial Teaching is an intervention method utilizing applied behavioral analysis. Many children on the more severe side of the autistic spectrum have deficits in learning basic abilities. DTT teaches skills through a structured ladder of small, easily-taught components. The method began in the 1970s through the efforts of Doctor Ivar Lovaas. Through repetition of the DTT process, children can obtain mastery over necessary abilities. The skills taught are classified as “cognitive, communication, play, social and self-help.”

 

There tends to be a lot of confusion between terms Discrete Trial Training (DTT) and Applied Behavioral Analysis (ABA). Often times when people talk about ABA programs for children with autism, they are actually referring to DTT. DTT is one of several types of teaching strategies that fall under the umbrella of ABA. So let’s tease the two apart.

ABA applies the science of “behaviorism,” to bring about meaningful change in an individual’s actions. It looks at behavior as a three step process:  the antecedent (a cue or instruction), the behavior and the consequence.

For example, when you’re hungry (antecedent), you eat something (behavior) and then you feel better (consequence). You enjoyed a positive consequence for your behavior, and this increases the likelihood that you’ll again eat when hungry in the future!

ABA applies this principle as an intervention to produce positive changes in behavior. Beyond the field of autism, it’s widely used to help individuals develop positive behaviors – such as good study habits. It’s also used to help those struggling with problem behaviors such as drug addiction.

In fact, most parents use a form of “ABA” on a daily basis, for example, by giving a child a “time out” for hitting or putting on a favorite movie after a child finishes his homework. Rewards and consequences can make a behavior more or less likely to happen again in the future. This relationship between the antecedent, behavior and consequence is what ABA is all about.

So how is DTT different?

DTT is a structured ABA technique that breaks down skills into small, “discrete” components. Systematically, the trainer teaches these skills one by one. Along the way, trainers use tangible reinforcements for desired behavior. For a child, this might include a candy or small toy.

 For example, a trainer teaching colors to a child might begin by teaching red. She would ask the child to point to red and then reward the behavior. She would then move on to teaching yellow by itself, reinforce that skill, and then ask about both colors. After the child learns all his colors, the trainer might teach the child to say each color’s name.

Many therapists have found DTT to be particularly effective for teaching skills to children with autism. DTT was one of the very first interventions developed for autism and has extensive research supporting it.

Are there other types of ABA that are effective for autism in addition to DTT?

Yes! Many of the effective early intervention approaches for autism are based on ABA principles, including the Early Start Denver Model (ESDM) and Pivotal Response Treatment (PRT). These are delivered in a more natural and less structured way than DDT. PRT is highly focused on whatever motivates the child. In PRT, for example, a child who is enjoying playing with a car and ramp might be asked to indicate a red versus blue car and then given the red car to roll down the ramp when he correctly points to it. ESDM similarly uses a natural environment but teaches multiple skills at once. So while teaching red, you may also be teaching turn-taking and other social skills.

All these types of ABA types of teaching include an instruction (antecedent), a response from the child (behavior), and a reward (consequence). The difference comes primarily in what types of rewards are used, and whether instructors use a highly structured format or use play and natural routines.

The 5 Principles of DTT

 The basics of DTT are stated in five principles. First, skills are broken down into small bites. Instructions are given in the most concise manner possible. Instead of asking a child to show the teacher which card on a table is red, the instructor may say simply, “touch red.” In this way, students avoid confusion about what the practitioner is asking. Second, the educator teaches each “bite” until the student masters it before moving on to another skill. Third, each session is intensive. Fourth, teachers begin with prompts as needed and then decrease them. Fifth, learning must be reinforced by incentives. The offering of these incentives and the point at which they are offered must be consistent. Dtteaching.com says that this early intervention technique is one of the main approaches therapists and educators use with children who exhibit autism.

What are the Training Steps of DTT?

There are five steps of DTT:

Discriminative Stimulus 

The discriminative stimulus is a brief clear instruction alerting the child to the task at hand. This helps the student make a connection between a specific direction and an appropriate response. An example could be when a teacher says: “what is this?” before asking a child to identify an object.

The Prompt

A prompt is not always given but, for some children, it may be necessary to help them form the proper response. When provided, it is performed between the discriminative stimulus and the response. A prompt is when the teacher shows the child the correct response to guide their behavior. For example, using the above example, a trainer may tap the correct object if it appears the child is having difficulty.

Child Response

The response is the behavior the child exhibits when presented with the discriminative stimulus. It is either going to be correct or incorrect. The target response is clearly defined ahead of time so the trainer knows exactly what behaviors are considered correct.

Consequence

 The consequence will vary according to the correctness of the response:

• Correct Response: A correct response is immediately reinforced with a positive reward. Often, the child is shown the reward ahead of time to know what they will be receiving. The reward may be verbal praise, food (e.g., a piece of candy), or a token from a behavioral modification system (e.g., a star that goes toward whatever they are earning). Whatever the reward, the type and amount are clearly specified before each trial.

• Incorrect Response: When a child gives an incorrect response during a DTT trial, they are simply corrected. The trainer tries to remain as neutral as possible and gives no reinforcement or punishment. For example, a teacher may point at the correct answer and say: “let’s try the next one”.

Inter-Trial Interval

The inter-trial interval is the last step of DTT. It is the period of time that occurs after the consequence. It indicates the end of one trial and the impending start of another. It is usually no more than five seconds. The shortness of the interval contributes to the continuity of the learning process.

How is DTT Different?

DTT is only one type of training that uses applied behavioral analysis. For instance, another teaching protocol, Incidental Teaching, focuses on naturally occurring events as teaching opportunities. The practitioner arranges an environment attractive to children and allows the child to prompt the teaching by showing interest in someone or something around him. The instructor then “elaborates” on the chosen item and elicits responses from the student. When the child reacts appropriately, he receives a “confirming response” or, in other words, a reward.

In Discrete Trial Teaching, however, the learning opportunity is engineered and structured by the practitioner. The process is as follows:

• Acquisition: the child accomplishes the initial lesson.

• Fluency: the child demonstrates the ability to repeat the skill and mastery of it.

• Maintenance: the student maintains the ability to perform the skill over time.

• Generalization: The child can apply the skill to a different environment or area.

Another difference between DTT and other types of ABA training is that sessions are more intensive than those in Incidental Teaching. This is because there are numerous quick sessions with very little lag time between trials. There is also the factor of social relevancy. Although a skill must be relevant for a child to want to learn it, DTT engineers sessions that teach skills that can be used in the environment whether or not they are needed in the instant. Incidental Teaching, in contrast, imparts skills as the need for them arises. In either method, the reward must be something which the child values, and it must be given immediately after the child learns the task.

The Value of DTT

As we learn more about autism, we will discover more and better ways to teach children how to communicate and interact in society to give them more normalcy in their lives. We now say that children “fall on the autism scale,” which is a way of saying that there are varying degrees of the condition. Any training method has to adapt to the level of cognition and communication the student possesses. Discrete Trial Teaching is an attempt to give children skills important to daily living that can be configured to the abilities of the student preparing them to have the fullest life possible.

In short, DTT is a concise step-by-step intervention tailored to improve a specific skill in the most efficient way possible. Its concentration on positivity and brevity allows for the productive shaping of important behavior in an easy-to-digest format. It has been a crucial intervention in assisting the autistic community for almost 50 years.