DTT stands for Discrete Trial Training, which is a highly structured teaching method used within the broader framework of Applied Behavior Analysis (ABA) to teach new skills to individuals, particularly those with autism spectrum disorder. Discrete Trial Training systematically breaks down complex skills into small, manageable steps, allowing for focused and efficient learning. This process provides a consistent and predictable learning environment, which is often beneficial for learners who struggle in less structured settings. The systematic nature of DTT also ensures that progress is accurately tracked through data collection, allowing instructors to make informed decisions about the teaching plan.
Deconstructing the Discrete Trial
The core mechanics of Discrete Trial Training are defined by the three-part sequence known as the A-B-C contingency: Antecedent, Behavior, and Consequence. The Antecedent is the clear, specific instruction or cue delivered by the instructor, which signals the learner to perform a specific action. For example, the instructor might say, “Touch nose,” while presenting a picture card or a target object. This instruction is designed to be the single, isolated prompt that begins the learning opportunity.
Behavior is the learner’s response to the Antecedent, which is the specific skill or action being taught. This response can be either correct or incorrect, and it is the moment where the learner demonstrates whether the skill has been acquired. The instructor observes the response and may provide a prompt, or physical assistance, to help the learner perform the correct action if necessary. Over time, these prompts are gradually reduced, or “faded,” to promote the learner’s independence.
The final component is the Consequence, which immediately follows the learner’s response. If the response is correct, a powerful positive reinforcer is delivered, such as praise, a preferred toy, or a small treat. This immediate reinforcement increases the likelihood that the learner will perform the correct behavior again in the future when presented with the same Antecedent. If the response is incorrect, the instructor uses a correction procedure, often involving a prompt, and withholds the positive reinforcer for that trial.
Implementing a DTT Session
The structure of a DTT session is highly controlled, often taking place in a distraction-free setting like a table in a quiet room, to minimize external variables that could interfere with learning. The teaching process relies on the rapid, repeated presentation of the A-B-C sequence, providing the learner with numerous opportunities to practice the target skill. This high frequency of trials is engineered to establish a strong connection between the instruction and the correct response.
A defining feature is the Inter-Trial Interval (ITI), which is the brief pause between the end of one Consequence and the presentation of the next Antecedent. This interval is kept extremely short, ideally lasting only a few seconds, to maintain the learner’s momentum and engagement. The quick pacing of trials maximizes the number of learning opportunities provided within a session.
Skills are typically introduced using massed trials, where the same instruction is repeated multiple times in a row. Once the learner begins to consistently respond correctly, the instruction is transitioned to mixed trials, also called random rotation, where the target instruction is interspersed with other mastered or new instructions. This shift from massed to mixed trials helps to ensure that the learner is responding to the specific instruction rather than simply memorizing a sequence. Throughout the entire session, the instructor collects precise data on every trial, recording the learner’s response, the type of prompt used, and whether the response was correct or incorrect. This meticulous data collection allows the behavior analyst to analyze performance trends and adjust the teaching program in real-time.
Why DTT is Used for Foundational Skill Building
Discrete Trial Training is particularly effective for teaching foundational skills because its structured nature minimizes the chance for errors and maximizes the learning rate. By breaking down complex abilities into their smallest components, DTT ensures that the learner masters each step before combining them into a full skill. This systematic approach is ideal for skills that require clear, non-negotiable responses, such as receptive identification of objects or imitation of motor actions.
The method also proves highly beneficial for establishing basic compliance and attention skills, which are necessary prerequisites for more complex learning environments. The controlled structure and immediate, consistent reinforcement create a powerful learning history, promoting motivation and focus. DTT helps learners acquire a baseline of abilities, including early language skills and basic academic concepts, that can then be used to access other teaching methods. The ultimate goal of using DTT is to build a robust repertoire of discrete skills that the individual can eventually generalize and apply in more natural, unstructured settings.