Discrete trial training (DTT)

Discrete trial training (DTT) is a technique for teaching students through a series of simplified steps. The task or skill to be taught is divided into several discrete steps, or trials, which are then presented in order. Students must learn to complete each step and do so successfully to complete the overall task or learn the entire skill. The development of DTT began in the 1970s and by the twenty-first century, it was a common means of education, particularly among young children with autism and related disorders.

Brief History

During the 1900s, understanding of mental and emotional differences between people developed at a brisk pace. Accordingly, so did methods of educating people with different backgrounds, conditions, and ability levels. The study of children with autism was an area of particularly great expansion and improvement.

Whereas in the past, children with severe autism might have been left untreated or institutionalized, modern researchers began to study the causes and effects of the disorder.

Meanwhile, educators—who were aware that a significant percentage of children may fall on the autism spectrum—searched for new ways to teach students of all ages with autism and similar disorders.

One of the main breakthroughs in the education of students with autism and other disabilities came in the early 1970s. A teacher and researcher named Dr. O. Ivar Lovaas began to study the learning abilities of children with severe autism. These children were unable to speak and had been kept in an institution where they received little, if any, advanced education. Lovaas created a method by which educators could teach these children basic verbal and communication skills through behavioral analysis.

The first applications of Lovaas’s procedures appeared promising, with many children demonstrating improved verbal abilities. However, the lasting effects of the lessons were cast into doubt. Upon completion of the lessons, some students returned to the institutions where they eventually lost the verbal skills they had developed. Meanwhile, other students went to live with their families, and in many cases these children were able to maintain and even further develop their abilities to communicate.

Lovaas continued his research and work with children. In the coming years, he focused on teaching children with autism who were younger, ranging from two to four years old, thus attempting to implant into their developing brains vital verbal skills that might last longer and lead to greater learning. Lovaas also worked more often in homes, where the environment was generally comfortable and supportive, rather than in institutions.

Overview

The techniques of O. Ivar Lovaas, known as the Lovaas method or early intensive behavioral intervention (EIBI), set the standards for the development of discrete trial training (DTT). DTT is a technique for teaching a new concept using a series of interconnected, simplified steps, rather than teaching the concept all at once, as a whole. Students learning through DTT can perform each smaller step in a prescribed order to build up to the completed whole skill or task.

Researchers find this technique to be effective for children with autism for several reasons but mainly because DTT can encourage these children to want to learn. Generally, many children with autism are not interested in learning like other students or find it too challenging to learn skills through watching and interacting with others. DTT takes a different approach to teaching and learning. It breaks down skills so that the lesson can be conducted in small, quick parts that may seem less strenuous, more rewarding, and less prone to risk of failure.

DTT can also increase student motivation because, in viewing a task as a series of steps, students with autism may gain a greater understanding of the procedures and reasoning behind the concept being taught, which can make learning more engaging and rewarding. Another advantage of DTT is that it allows each student to receive personal attention and customization, so educators can base lessons around the child’s educational and behavioral strengths and weaknesses.

In a DTT lesson, the steps, or trials, involved in a lesson are carefully scripted. Generally, they are designed to be brief in duration, clear in their expectations, and lead to a tangible result. Trials may seem deceptively simple, but DTT educators structure trials carefully around six basic parts. These parts are the antecedent, the prompt, the response, the correct consequence, the incorrect consequence, and an interval between trials.

The first step of a DTT lesson is the antecedent, which is information set up by the educator and presented to the student before the task begins. The antecedent helps to create the context in which the student should respond. For instance, in a lesson about numbers, the antecedent might include flashcards with numbers on them or a pile of small objects to be counted, as well as a brief description of the trial.

Stemming from the antecedent is the prompt, which is a description or demonstration of what the student needs to do to successfully complete the task. For example, a student might have to move pennies from one pile to another in a counting lesson. As part of the prompt, the educator may model moving the pennies to show how it is to be done. As the lesson continues, the educator usually reduces the modeling and allows the student to work more independently.

The response step of DTT outlines the exact result the student will need to perform in order to pass the trial. In documentation, the response must be described specifically. It is not enough to say that the student must answer correctly. Rather, the response should specify that the student must, for instance, move five pennies from the first pile to the second pile.

The next two steps in DTT relate to reinforcement of the student’s behaviors, namely the consequences for correct or incorrect answers. Educators generally reward correct answers with positive reinforcements such as praise or small rewards like candy or extra points. Educators must decide how often, and how much, positive reinforcement to apply in each step of the lesson. Similarly, educators must choose a consequence for incorrect answers. These are usually mild but clear negative symbols, such as the word “no” or the removal of materials from the table.

The final step of DTT, which is not generally noted in documentation but rather is taken for granted, is a brief inter-trial interval, or pause between trials. This pause is helpful to signal the end of the trial and allow time for the student to reflect on the actions taken and the results achieved. Intervals are usually limited to a few seconds to avoid losing the student’s attention.

Applied Behavioral Analysis (ABA) is a similar concept to DTT that is also used to help influence and adjust an individual's actions. However, the main different between ABA and DTT is that DTT breaks down the desired outcome into smaller, manageable, discrete steps. ABA is the broader concept of the antecedent (instruction or cue), behavior (response), and consequence (reward). Generally, when referring to direct instruction in the classroom, teachers use DDT to walk students through lessons and concepts.

Bibliography

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“Why Discrete Trials Work.” Lovaas Institute, 7 Sept. 2018, www.lovaas.com/meetingpoint-2007-09-article-04.php. Accessed 24 Oct. 2018.