Discrete Trial Training (DTT): Step-by-Step Examples

Michael Mohan

June 3, 2025

Discrete Trial Training (DTT): Step-by-Step Examples makes teaching new skills structured, simple, and effective.

What is Discrete Trial Training (DTT)?

Discrete Trial Training (DTT) is a structured teaching method primarily used in Applied Behavior Analysis (ABA) therapy to help children with autism spectrum disorder (ASD) and other developmental disabilities learn new skills. This evidence-based approach breaks down complex skills into smaller, manageable components and teaches them systematically through repeated practice and reinforcement.

DTT was first developed by Dr. Ivar Lovaas in the 1960s and has since become one of the most widely researched and implemented interventions for autism. Research shows that intensive DTT programs can lead to significant improvements in IQ, language development, and adaptive behaviors in children with autism.

The Core Components of Discrete Trial Training

1. Discriminative Stimulus (SD)

The discriminative stimulus is the instruction or cue that signals the child to perform a specific behavior. This could be a verbal instruction like “Touch red” or a visual cue such as holding up a red card.

2. Response

The response is the child’s behavior following the discriminative stimulus. This can be verbal (saying a word), motor (pointing to an object), or any other measurable behavior.

3. Consequence

The consequence follows the child’s response and can be either reinforcement (for correct responses) or correction (for incorrect responses). Positive reinforcement is crucial for maintaining motivation and encouraging learning.

4. Inter-Trial Interval (ITI)

The inter-trial interval is the brief pause between trials, typically lasting 3-5 seconds. This allows the child to process the information and prepare for the next trial.

Why DTT is Effective: The Research Behind the Method

According to a comprehensive meta-analysis published in the Journal of Autism and Developmental Disorders, DTT interventions show significant positive effects across multiple skill domains. Specifically:

Language Development: Children receiving DTT show an average improvement of 1.2 standard deviations in expressive language skills
Cognitive Abilities: IQ gains of 15-25 points have been documented in intensive DTT programs
Social Skills: 78% of children show measurable improvements in social interaction skills after 6 months of DTT
Adaptive Behaviors: Daily living skills improve by an average of 40% within the first year of implementation

The National Professional Development Center on Autism Spectrum Disorder recognizes DTT as an evidence-based practice, citing over 25 high-quality research studies supporting its effectiveness.

Step-by-Step DTT Implementation Guide

Phase 1: Assessment and Goal Setting

Step 1: Conduct Initial Assessment Before beginning DTT, conduct a comprehensive assessment to identify the child’s current skill levels, learning preferences, and areas of need. Use standardized assessment tools such as the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP) or the Assessment of Basic Language and Learning Skills (ABLLS-R).

Step 2: Develop Specific Learning Objectives Create measurable, observable goals based on the assessment results. For example:

“Child will receptively identify 10 common objects with 80% accuracy across 3 consecutive sessions”
“Child will imitate 5 gross motor actions with 90% accuracy”

Phase 2: Setting Up the Learning Environment

Step 3: Prepare Materials Gather all necessary materials before beginning the session. This includes:

Visual aids and teaching materials
Data collection sheets
Reinforcers (preferred items or activities)
Timer for inter-trial intervals

Step 4: Minimize Distractions Create a distraction-free environment by:

Removing unnecessary items from the table
Ensuring good lighting
Positioning chairs appropriately for easy interaction

Phase 3: Conducting DTT Sessions

Step 5: Present the Discriminative Stimulus Present the instruction clearly and consistently. Use the same wording each time to avoid confusion. For example, if teaching color identification, always say “Touch blue” rather than varying between “Touch blue,” “Find blue,” or “Show me blue.”

Step 6: Prompt if Necessary If the child doesn’t respond within 3-5 seconds, provide a prompt. Use the least intrusive prompt necessary:

Verbal prompt: “Touch the blue one”
Gestural prompt: Point to the correct item
Physical prompt: Guide the child’s hand to the correct response

Step 7: Provide Immediate Consequence

Correct Response: Provide enthusiastic praise and preferred reinforcer immediately
Incorrect Response: Say “Try again” or “No” in a neutral tone, then provide the correct answer

Step 8: Record Data Document each trial’s outcome immediately to track progress accurately.

Detailed DTT Examples by Skill Domain

Example 1: Receptive Identification (Colors)

Target Skill: Child will receptively identify primary colors

Materials: Red, blue, and yellow cards

Trial Sequence:

SD: Therapist places three colored cards in front of child and says “Touch red”
Response: Child touches the red card
Consequence: “Great job! You touched red!” + preferred reinforcer
ITI: 3-second pause
Next Trial: “Touch blue”

Data Collection: Record “+” for correct, “-” for incorrect, “P” for prompted

Progression: Start with 2 colors, add third color when child achieves 80% accuracy

Example 2: Expressive Labeling (Body Parts)

Target Skill: Child will expressively label body parts

Materials: None required

Trial Sequence:

SD: Therapist points to their own nose and asks “What’s this?”
Response: Child says “nose”
Consequence: “Excellent! That’s your nose!” + high-five
ITI: 4-second pause
Next Trial: Point to ear, “What’s this?”

Prompting Hierarchy:

Full verbal prompt: “Nose”
Partial verbal prompt: “N…”
No prompt

Example 3: Imitation (Motor Actions)

Target Skill: Child will imitate gross motor actions

Materials: None required

Trial Sequence:

SD: Therapist says “Do this” while clapping hands
Response: Child claps hands
Consequence: “Nice clapping!” + preferred toy for 10 seconds
ITI: 5-second pause
Next Trial: “Do this” while touching head

Teaching Tips:

Start with simple, one-step actions
Use exaggerated movements
Ensure child is paying attention before presenting SD

Advanced DTT Strategies and Troubleshooting

Managing Challenging Behaviors

Problem: Child frequently engages in escape behaviors Solution:

Reduce session length
Increase reinforcer quality
Incorporate movement breaks
Check task difficulty level

Problem: Child shows prompt dependency Solution:

Implement systematic prompt fading
Use time delay procedures
Vary prompt types
Ensure reinforcement is contingent on independent responses

Data-Driven Decision Making

Successful DTT implementation requires continuous data analysis. Track the following metrics:

Acquisition Rate: Number of trials to reach mastery criterion
Maintenance: Retention of skills over time
Generalization: Use of skills across different settings and people
Response Latency: Time between SD and response

Generalization Strategies

To ensure skills transfer beyond the therapy setting:

Vary Teaching Examples: Use multiple exemplars of the same concept
Change Instructors: Have different people present the same trials
Modify Settings: Practice skills in various environments
Natural Environment Training: Incorporate learning opportunities into daily routines

Common Mistakes to Avoid in DTT

1. Inconsistent Presentation

Varying the discriminative stimulus can confuse the learner. Maintain consistency in wording, tone, and presentation style.

2. Delayed Reinforcement

Reinforcement must be immediate to be effective. Any delay reduces the association between the correct response and the positive consequence.

3. Over-Prompting

Providing prompts too quickly prevents independent learning. Allow sufficient response time before prompting.

4. Inadequate Data Collection

Accurate data is essential for monitoring progress and making informed decisions about program modifications.

5. Ignoring Motivation

Failing to assess and update reinforcer preferences can lead to decreased motivation and slower learning.

Measuring Success: DTT Outcomes and Progress Monitoring

Key Performance Indicators

Accuracy: Percentage of correct responses across trials

Acquisition Phase: 50-79% accuracy
Mastery Phase: 80% or higher across 3 consecutive sessions

Response Latency: Time between instruction and response

Target: 3 seconds or less for mastered skills

Retention: Maintenance of skills over time

Conduct probe sessions weekly to assess retention

Long-Term Outcomes

Research demonstrates significant long-term benefits of intensive DTT programs:

Educational Placement: 47% of children receiving intensive DTT are placed in mainstream classrooms compared to 2% of controls
Language Development: Average vocabulary increases from 50 words to over 1,000 words within two years
Independence: 60% of children show significant improvements in daily living skills

Technology Integration in Modern DTT

Digital Data Collection

Modern DTT programs increasingly utilize tablet-based applications for:

Real-time data entry
Automated progress graphs
Immediate feedback to therapists
Parent portal access for home data

Virtual Reality Applications

Emerging research shows promise for VR-enhanced DTT, particularly for:

Social skills training
Safety skill instruction
Generalization to community settings

Cost-Effectiveness and Insurance Considerations

DTT programs typically require 20-40 hours per week of intensive intervention. While the initial cost is significant, research indicates:

Return on Investment: Every dollar spent on early intensive intervention saves $3-5 in special education costs
Insurance Coverage: Most states now mandate autism therapy coverage, including DTT
Medicaid Coverage: Available in all 50 states for qualified families

Future Directions and Emerging Trends

Precision Teaching Integration

Combining DTT with precision teaching methods shows promise for:

Faster skill acquisition
Better retention rates
More efficient use of therapy time

Parent-Implemented DTT

Training parents to implement DTT procedures:

Increases practice opportunities
Improves generalization
Reduces overall program costs
Enhances family involvement

Conclusion

Discrete Trial Training remains one of the most effective, evidence-based interventions for children with autism spectrum disorder. When implemented correctly with proper planning, consistent execution, and continuous data monitoring, DTT can produce significant improvements in language, cognitive, social, and adaptive skills.

The key to successful DTT implementation lies in:

Thorough initial assessment
Clear, measurable objectives
Consistent trial presentation
Immediate reinforcement
Systematic data collection
Regular program modifications based on data

As the field continues to evolve, integrating technology and expanding to parent-implemented models will likely increase DTT’s accessibility and effectiveness. For families and professionals considering DTT, the extensive research base provides confidence in its potential to create meaningful, lasting improvements in children’s lives.

Remember that DTT is most effective when part of a comprehensive treatment plan that may include other ABA techniques, speech therapy, occupational therapy, and educational interventions. Consultation with qualified professionals is essential for developing and implementing an effective DTT program tailored to each child’s unique needs.

References

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