discrete-trial-teaching

name	discrete-trial-teaching
description	Use when designing or implementing discrete trial teaching (DTT) programs, structuring mass or distributed trial blocks, selecting error correction procedures, or troubleshooting skill acquisition in structured teaching formats.

Discrete Trial Teaching (DTT)

Discrete trial teaching is a structured, clinician-directed instructional format in which each learning opportunity is presented as a distinct unit with a clear beginning, teaching interaction, and end. DTT is the backbone of many early intensive behavioral intervention (EIBI) programs and remains one of the most empirically supported procedures for teaching new discriminations and building foundational repertoires.

Trial Components

Every discrete trial contains five elements presented in a predictable sequence:

1. Discriminative Stimulus (S^D)

The instruction, question, or cue that signals reinforcement is available for a correct response. The S^D must be:

• Clear and concise (avoid extraneous language)
• Delivered when the learner is attending (establish attending before presenting S^D)
• Consistent across trials during acquisition, then varied during generalization
• Distinguishable from background stimulation

2. Prompt (if needed)

An additional stimulus provided simultaneously with or immediately after the S^D to increase the probability of a correct response. The type and level of prompt depend on the learner's skill level and the prompt fading strategy in use. Prompts are temporary — the goal is always to transfer stimulus control from the prompt to the S^D.

3. Response

The learner's behavior following the S^D (and prompt, if provided). Define the target response topography in advance so that correct, incorrect, and no-response outcomes are objectively identifiable. Set a response interval (typically 3–5 seconds) after which no response is scored as incorrect.

4. Consequence

• Correct response: Deliver reinforcement immediately. Vary reinforcers to prevent satiation. Use descriptive praise paired with tangible/edible reinforcers during early acquisition; fade to social reinforcement as skill strengthens.
• Incorrect response or no response: Implement the designated error correction procedure. Do not deliver reinforcement for errors. Use a neutral, instructional tone — avoid punitive reactions.

5. Inter-Trial Interval (ITI)

A brief pause (typically 1–5 seconds) between the consequence and the next S^D. The ITI serves as a temporal boundary between trials, allows the clinician to record data, and provides a brief reset. Shorter ITIs increase trial density; longer ITIs may reduce frustration and prompt dependency.

Trial Arrangements

Mass Trials

Multiple consecutive trials targeting the same skill. Useful during initial acquisition when the learner needs repeated practice with a single target. Risk: rote responding and decreased motivation.

Distributed Trials

Trials for a given target are spread across a session with other targets interspersed between them. Supports maintenance and discrimination. More closely approximates natural learning conditions.

Interspersed (Easy-Hard-Easy)

Alternate between mastered (maintenance) targets and acquisition targets. Benefits:

• Maintains high rates of reinforcement
• Increases momentum and on-task behavior (behavioral momentum)
• Reduces escape-maintained problem behavior
• Provides discrimination training (different S^Ds require different responses)

A common ratio is 80% mastered to 20% acquisition targets, adjusted based on the learner's tolerance and performance.

Error Correction Procedures

4-Step Error Correction

1. Model: Immediately re-present the S^D and provide the correct response ("This is ___")
2. Prompt: Re-present the S^D with a controlling prompt to evoke the correct response
3. Transfer trial: Re-present the S^D with a reduced or no prompt; reinforce at a lower magnitude than an unprompted correct
4. Distractor trial: Insert a brief mastered trial, then re-present the original S^D to verify the correction held

Backstep Error Correction

After an error, return to the last step in the prompt hierarchy where the learner was successful, then re-fade from that point. Particularly useful when errors indicate the prompt was faded too quickly.

Simple Correction

Re-present the S^D with a controlling prompt, obtain the correct response, and move on. Fastest procedure; useful when session pacing is critical and the learner has a low tolerance for repeated trials on errors.

Errorless Learning and Errorless Transfer

Errorless learning presents the controlling prompt simultaneously with the S^D from the first trial, preventing errors from occurring. The clinician then systematically fades the prompt across trials using time delay or stimulus fading. Benefits:

• Eliminates error patterns before they establish
• Reduces frustration and escape behavior
• Particularly effective for learners with extensive error histories or prompt dependency

Errorless transfer moves stimulus control from the prompt to the S^D without allowing errors at any fading step. If an error occurs at a given fading step, the clinician returns to the previous level rather than correcting forward.

Data Collection During DTT

Record the following for each trial or trial block:

• Response type: Independent correct (+), prompted correct (P), incorrect (−), no response (NR)
• Prompt level: Full physical, partial physical, model, gestural, verbal, independent
• First-trial data: The response on the first unprompted trial of each session is the most sensitive measure of acquisition
• Mastery criteria: Define in advance (e.g., 80% independent across 2 consecutive sessions, or 90% across 3 sessions with at least 2 therapists)
• Probe data: Periodic cold probes (first trial of session, no prompt) to assess true independent performance

When to Use DTT

DTT is indicated when:

• Teaching a new skill that does not occur in the learner's repertoire
• Training discriminations (matching, receptive identification, tacts)
• Building isolated component skills that will later be chained into complex sequences
• The learner requires high repetition rates to acquire skills
• Precise data on trial-by-trial performance is needed
• Teaching listener responding, imitation, or intraverbal fill-ins

Advantages

• High trial density produces rapid acquisition for many learners
• Precise data allow objective mastery decisions
• Systematic prompt fading and error correction reduce ambiguity
• Well-suited for training staff and parents due to clear procedural steps

Limitations

• Artificial structure may not promote generalization without explicit programming
• Risk of prompt dependency if fading is not systematic
• May reduce intrinsic motivation if reinforcement is not carefully managed
• Responses may become rote or stimulus-bound
• Not ideal for teaching spontaneous, self-initiated, or social behavior

Combining DTT with Other Procedures

DTT is most effective as part of a comprehensive program that also includes natural environment teaching (NET), incidental teaching, and generalization programming. Skills acquired in DTT should be programmed for generalization across settings, people, stimuli, and response variations. Use DTT for initial acquisition, then transition to naturalistic formats for fluency, maintenance, and generalization.

Key References

• Cooper, J. O., Heron, T. E., & Heward, W. L. (2020). Applied Behavior Analysis (3rd ed.). Pearson.
• Lovaas, O. I. (1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting and Clinical Psychology, 55(1), 3–9.
• Smith, T. (2001). Discrete trial training in the treatment of autism. Focus on Autism and Other Developmental Disabilities, 16(2), 86–92.
• Leaf, R., & McEachin, J. (1999). A Work in Progress: Behavior Management Strategies and a Curriculum for Intensive Behavioral Treatment of Autism. DRL Books.
• Ghezzi, P. M. (2007). Discrete trials teaching. Psychology in the Schools, 44(7), 667–679.