Discrete Trials Training
Discrete trials training (DTT) is the oldest and most commonly used behavioral intervention technique used in teaching children with autism spectrum disorders (ASD) life and social skills such as communication. This technique is based on the work of Dr. Ivar Lovaas and falls under the overall category of Applied Behavior Analysis (ABA).
DTT focuses on changing observable behaviors by using successive approximations of behaviors and shaping new responses. A skill must be broken down into small parts and taught in steps. Reinforcement plays a key role in the success of this treatment. DTT also focuses on being clear and concise in commands and is the overall treatment of choice by most parents and therapists.
Dr. Ivar Lovaas and Dr. Robert Koegel of the University of California Los Angeles (UCLA) are recognized for developing DTT in the 1970s. Dr. Lovaas based his research on the fact that if children are rewarded for behaviors they will repeat them. He started DTT research at UCLA with 38 children and was able to conclude that of the 19 children in his treatment group, 47% were able to reach normal IQ level after 2 years of his interventions. In a follow-up he was able to prove long-lasting effects when analyzing the nine children who were successful in the original study and had sustained high functioning.
Other researchers have been partially successful in replicating Lovaas’s success. These researchers include Dr. James Mulick of Ohio State University, who is known for finding an association between DTT and early intervention in raising the IQ scores of children with autism.
Methods of Providing Intervention
The Trainer’s Presentation
The trainer must begin by prompting the child to do a task or identify something. For example “Do this” or “What is this?” The command must be clear and concise and the trainer often must direct the child’s response such as guiding their hands.
The Child’s Response
The child gives a correct or incorrect response to the trainer’s cue.
If the child exhibits the correct response it must immediately be followed with reinforcement. Reinforcement will vary for different children and can range from rewards such as food or tokens to verbal praise. If the response is incorrect, the trainer says “No” and removes the teaching materials or signals the response was incorrect in some other way.
Short Pause Between Consequence and Next Instruction
After giving consequence, the trainer must pause for a short period such as 5-15 seconds before going on to the next trial and repeating the steps.
Recent research has been based more on how to teach individuals DTT intervention techniques as opposed to if the treatment is effective. Individuals who have been researched in this section include university students, teachers, parents, and direct care staff.
Self-instructional manual and checklists
Self-instructional manuals are one form of teaching DTT to prospective trainers. A study was done at the University of Manitoba in which accuracy increased substantially after giving students a manual to read. Manuals can be effective, especially for people who need a better idea of what DTT is and what is to be expected of them. Also, a trainer can use the manual as a resource to go back to if they have questions.
Checklists are often important in analyzing if DTT intervention is effective or to provide trainers with steps to implementing DTT. Experimenters used a checklist to analyze video recordings of participants and found it was an effective way to gauge accuracy. Trainers can use the steps on the checklist to learn the methods needed to implement DTT and having a checklist to refer to can be really important in promoting generalization.
Video recording is very important in training DTT as well as assessing accuracy. Video recordings are often used to teach the methods of DTT. Video recordings can be very useful in showing a scenario to learners that is representative of an actual session of DTT. Also, it is very cost effective because a video can be shown over and over. Video training is often used in training any job or skill and has shown to be an effective way to teach DTT. Video recording is also very useful to look back at a study and code the data such as how many times a behavior occurred.
The use of modeling is important for teaching DTT. In DTT, the learner views the instructor implement part of the treatment and is expected to watch and be able to repeat the methods and steps that they were shown. Modeling is often very effective with learners who do not have an extensive knowledge of DTT because it allows them to see what they need to do.  It can also be effective with people who have worked hands on with children with autism because they are often implementing treatments, but do not know the methods they are using by name.
There is some controversy surrounding the use of the word Training in DTT because in the United States this term is more commonly used for non-human teaching such as obedience training with dogs.
- Ghezzi, P. M. (2007). Discrete Trials Training. Psychology in Schools, 44 (7), 667-679. doi: 10.1002 /pits.20256
- The History of Applied Behavior Analysis: It’s not just Discrete Trial Teaching., Rothstein, A. (2008).
- ABA for Autism., Behavioral Neurotherapy Clinic. (2009).
- Thiessen, C., Fazzio, D., Arnal, L., Martin, G. L., Yu, C. T., & Keilback, L. (2009). Evaluation of a Self-Instructional Manual for Conducting Discrete-Trials Teaching With Children With Autism. Behavior Modification, 33 (3) 360-373. doi: 10.1177/0145445508327443
- Lafasakis, M., & Sturmey, P. (2007). Training Parent Implementation of Discrete-Trial Teaching: Effects on Generalization of Parent Teaching and Child Correct Responding. Journal of Applied Behavior Analysis, 40 (4). 685-689. doi: 10.1901/jaba.2007.685-689
- Catania, C., Almedia, D., Lui-Constant, B., & Reed, F.D. (2009). Video Modeling to Train Staff to Implement Discrete-Trial Instruction. Journal of Applied Behavior Analysis, 42 (2), 387-392. doi: 10.1901/jaba.2009.42-387
- Dib, N., & Sturmey, P. (2007). Reducing Student Stereotypy by Improving Teachers’ Implementation of Discrete-trial Training. Journal of Applied Behavior Analysis, 40(2), 339-343. doi: 10.1901/jaba.2007.52-06