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What is Discrete Trial Training (DTT)?

A step-by-step guide to one of the most fundamental ABA teaching techniques.

April 6, 2026·7 min read

Discrete Trial Training (DTT) is a structured ABA teaching method that breaks skills into small, teachable components. Each “trial” has five parts: a cue (SD), an optional prompt, a response, a consequence, and a brief pause. DTT is used to teach everything from labeling objects to social skills, and is one of the most tested concepts on the RBT® exam.

The 5 Components of a Discrete Trial

1

Discriminative Stimulus (SD)

The therapist presents a clear instruction or cue. This tells the learner that reinforcement is available for a correct response.

Example: The RBT places three picture cards on the table and says, "Touch dog."

2

Prompt (if needed)

If the learner doesn't respond or responds incorrectly, the therapist provides assistance. Prompts are faded over time to build independence.

Example: The RBT gently guides the child's hand toward the dog card (physical prompt).

3

Response

The learner performs a behavior — either correct, incorrect, or no response. The therapist records the response for data collection.

Example: The child touches the dog card independently.

4

Consequence

The therapist delivers a consequence based on the response. Correct responses receive reinforcement; incorrect responses receive a correction procedure.

Example: Correct: "Great job! That IS the dog!" + token/preferred item. Incorrect: "Let me show you" + model correct response.

5

Inter-Trial Interval (ITI)

A brief pause (1-5 seconds) between trials. This creates a clear separation between each learning opportunity and gives the learner a moment to reset.

Example: The RBT pauses for 3 seconds, clears the cards, and re-presents them in a new arrangement.

Common DTT Mistakes (Avoid These on the Exam)

  • Running trials too fast without clear ITIs — the learner can't distinguish between trials.
  • Delivering reinforcement for prompted responses the same way as independent responses.
  • Using the same prompt level repeatedly instead of fading prompts systematically.
  • Not collecting data during sessions — you can't measure progress without data.
  • Presenting the SD before the learner is attending (looking at materials, seated, etc.).

Practice DTT Questions

Our mock exams include DTT scenarios — test your understanding now.

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