The discrete trial is a very common teaching method for a number of the behaviorally-based interventions used in teaching children with autism spectrum disorders (ASD). In fact, Discrete Trial Training (DTT) is often synonymous with Applied Behavior Analysis (ABA), although it shouldn't be as they are very different things. ABA is a science and DTT is a teaching methodology that uses the principles of ABA.
Discrete trial training is usually associated with the work of O. Ivar Lovaas. Discrete trial training consists of a series of discrete lessons or trials taught usually with one student and one adult. Each trial consists of three main components; an antecedent, a "directive" or request for the individual to perform a particular action; a behavior, or "response" from the person; and a consequence, a "reaction" from the therapist based upon the response of the person, it is usually reinforcement or a correction of some kind to shape future correct responses. Reinforcers are selected by evaluating the individual's preferences. Many students initially respond to tangible reinforcers such as food items. These artificial reinforcers are faded quickly and replaced with natural reinforcers such as praise, tickles, hugs, task completion, and social interaction.
Children with ASD often face many deficits and difficulties in learning (Romancyzk in Maurice, 1996). Discrete-trial training can help to compensate for these difficulties. The person's progress is closely monitored by the collection of data on the performance of each trial. After a skill has been mastered, another skill is introduced, and the mastered skill is placed on a maintenance schedule. A maintenance schedule allows for periodic checking so the person does not regress in mastered skills. Discrete Trial Training programs often start by training learning readiness skills (sitting, attending, looking at the teacher), social skills (looking at people, talking and interacting with them appropriately, smiling in response to a social interaction), safety skills (responding to and stating name, address, and phone number) and basic concepts (vocabulary, colors, letters, numbers). Children who are non-verbal may be trained to speak, use sign language, or use other communication devices such as PECS. After these basics are mastered, higher-level skills are trained. Discrete trial training is a technique that can be an important element of many early learner comprehensive educational programs. Depending on the student, eventually a much less intensive, informal approach of DTT may be implemented by a knowledgeable professional to teach more complex language, communication, and social interaction skills in more natural learning environments. (See PRT, incidental teaching, and generalization)