Applied Behavior Analysis: Discrete Trial Training (DTT)

Applied Behavior Analysis (ABA) methods are early intervention programs for children with autism which are based on the theory that behavior which is rewarded is more likely to be repeated than behavior which is ignored. ABA techniques are used to support children with autism in a variety of ways, including: teaching new skills; increasing and / or maintaining behaviors; and restricting or reducing interfering behaviors. Discrete Trial Training (DTT), made popular by Dr. Ivan Lovaas is a proven method to increase skill acquisition through mass trails under the direction of a behaviorally trained therapists.

Lovaas Therapy is an ABA-based program developed by Ivar Lovaas, Ph.D., at the UCLA Clinic for the Behavioral Treatment of Children. Dr. Lovaas began studying methods of treating young children with severe autism in about 1965. He reported on the results of his work with a group of autistic preschoolers (starting under age 4) in a major study in 1987 and a follow-up study in 1993.

Lovaas Therapy aims to teach "learning readiness" skills such as sitting in a chair and attending, and decreasing behaviors that interfere with learning, such as noncompliance, tantrums and aggression. In addition, the basic rules of social interaction are established. Children are taught how to learn from the environment through the introduction of clear stimulus-response-reward cycles.

The Lovaas Therapy uses an ABA method called Discrete Trial Training (DTT), in which the autistic child is challenged with individual learning opportunities. After mastering a specific training trial, the child then builds upon the learned skill to tackle a more complex one. Lovaas Therapy consists of a series of distinct repeated lessons or trials taught one-to-one. Typically the lessons are highly intensive, usually taking 30-40 hours per week, and conducted by a trained therapist in the family’s home (in some cases, a much less intensive, informal approach of Lovaas Therapy may be implemented to teach specific skills such as sitting and attending). Treatment begins with two primary goals: teaching "learning readiness" skills such as sitting in a chair and attending, and decreasing behaviors that interfere with learning, such as noncompliance, tantrums and aggression. Each trial consists of a request for the individual to perform an action, behavior, or response, and involves a consequence or reaction from the therapist. Positive reinforcers are selected by evaluating the individual's preferences - many children initially respond to rewards such as food items; however these concrete reinforcers usually are replaced as soon as possible with rewards such as praise, tickles, and hugs.

The difference between Lovaas and Verbal Behavior (VB)
Applied Behavior Analysis (ABA) over the past 15 years or so has mistakenly been referred to as Lovaas Programming when referring to its use with children with autism. With such a major increase in the interest and use of Verbal Behavior (VB) as a component in ABA programs, it is necessary to explain how ABA, Lovaas programming and Verbal Behavior differ and relate. As the science of ABA evolves, improvements to the application of its principles are carefully researched and published in peer reviewed journals. In the past, most ABA programs implemented for children with autism were based on the work published by Ivar Lovaas in the 1980’s. However, during those years Jack Michael, PHD., Mark Sundberg, PHD., and James Partington, PHD., among others in the field, focused on researching B.F. Skinner’s Analysis of Verbal Behavior and its effectiveness of teaching language skills. This research has improved ABA programs by emphasizing the important elements in language acquisition previously ignored by traditional Lovaas-based programs. *That is, capturing a child’s motivation to develop a connection between the value of a word and the word itself.
While the Lovaas-based approach uses ABA to teach language skills based on the premise that receptive language should be developed prior to expressive language…
The Verbal Behavior approach focuses on teaching specific components of expressive language (mands, tacts, intraverbals, among others) first.
This approach begins with what is called mand training… this teaches a child to request desired items, activities, and information. Therefore teaching the child that “words” are valuable and lead them to getting their wants and needs met. Another difference lies within the emphasis of “function” (Verbal Behavior) of language, instead of “form” (Lovaas-based). For example, in a VB program, a child is first taught to ask for a “cookie” any way they can (vocally, sign language, etc.) only when they actually want a cookie. They capture that desire for a cookie and turn it into the lesson that the word (or sign) for a cookie will get you what you want… A Cookie! In a Lovaas-based program, the child may be taught to say the word “cookie” while other words are also repeatedly taught but not necessarily when the child wants a cookie at that moment.
One of the primary ideas behind Verbal Behavior approach is that the meaning of a word is found in its function and not in the word itself. If you don’t take into account the function of language you often end up with a child who may be able to label or identify hundreds of objects but never uses them in functional ways or spontaneously requests them in the natural environment.

When using a Verbal Behavior approach, you teach each word or object across all functional relations to that word or object.
Verbal Behavior Terms:

Mand: Requesting wants and needs

Tact: Labeling or describing objects

Receptive repertoire: Non-verbally following directions, discriminating between pictures and objects

Imitation: Repeating, copying what was observed

Echoic: Vocal imitation

Intraverbal: Verbally (or using sign language) responding to the verbal behavior of others

Textural: reading

Transcriptive: Writing


Obviously you cannot teach all these components at once, but with some of these skills in the child's repertoire it is possible to build all of these various language components earlier than once thought.
In a traditional Lovaas approach the concept of "cookie" may be considered mastered when a child can point to a cookie and say cookie when shown a cookie, but with a Verbal Behavior approach the concept of "cookie" is not considered mastered until the child can:

Ask for a cookie when it is wanted (mand)

Find the cookie when it is asked for (receptive)

Select a cookie if asked:

What do you eat? (function)

What has chocolate chips? (feature)

Find the food (class)

Answer questions about the cookie when it is not present: (intraverbals)

Tell me what you eat?

What has chocolate chips?

What’s crunchy?


In summary, traditional Lovaas programming and Verbal Behavior are two distinct approaches to using the principles of ABA to better the lives of children with autism. Although Lovaas style programming has been in the spotlight longer, more and more people are going to an ABA program with an emphasis on Verbal Behavior as it is showing the ability to bridge the gaps left in traditional ABA programs.

A recent American internet survey was conducted to see what interventions were most effectively being used to help children with Autism spectrum or related disorders. The results for 72 children listed therapies such as Sensory integration, Occupational therapy, speech, special diets (GFCF, Feingold, etc), vitamins, Pecs, Secretin, Floortime/Greenspan, digestive enzymes and Paxil. According to the survey, ABA/VB was by far the most effective intervention ranked by parents. No other therapy even ranked close.

top