The difference between Discrete Trial Training (DTT) and Applied Behaviour Analysis (ABA) can be confusing, with some interchanging terms. However, DTT and ABA are not synonymous, rather DTT is a teaching technique based on the principles of ABA and is often used during various therapies and in the educational setting. This article will take a deep dive into DTT, distinguishing it from ABA, discussing what it is, how it is implemented, and how it can benefit children with Autism Spectrum Disorder (ASD).
- What is Discrete Trial Training?
- Is Discrete Trial Training ABA Therapy?
- What are The Benefits of DTT?
- Key Principles of DTT
- How is DTT Performed?
- Challenges and Criticisms of DTT
- Future Directions and Innovations in DTT
- Frequently Asked Questions
What is Discrete Trial Training?
DTT is a teaching technique that takes a skill a child must learn and breaks it down into smaller components taught in a graduated way. It consists of repeated trials in a 1:1 setting with the child receiving prompts to guide correct responding followed by reinforcement. This technique was developed in the 1980s by Dr. Ivar Lovaas as part of The Lovaas Method which primarily consists of discrete trials.
According to ABA principles, a child is more likely to adopt a skill when rewarded and less likely to continue an inappropriate behavior when they receive no reward or a negative outcome. DTT embodies these principles through its structured sequence, following the ABCs (Antecedent-Behavior-Consequence) of ABA. First, there is a cue or instruction (Antecedent), then a prompt and response (Behavior). The sequence is completed with a reward (Consequence) and a pause before the next trial.
DTT is characterized by a clear structure that uses a predictable framework. The sessions are short and highly focused with several repetitions – some can consist of 10 trials per skill. The learner is prompted to avoid errors thus ensuring a consistent delivery of reinforcement. Each skill is taught to mastery before moving to another skill. The interactive nature of DTT and the quick pace of the trials keep learners motivated and engaged as they progress from simple to complex tasks.
DTT can be performed by anyone trained in the method. Most ABA programs that use DTT are developed by Board Certified Behavior Analysts (BCBAs) but can be implemented by special educators, speech and language pathologists, psychologists, occupational therapists, registered behavior technicians, and other aides.
DTT was designed to be used with children with severe forms of Autism between the ages of two and six years. However, studies have shown that DTT can also be effective when used with older children (6-11 years). For example, Gould et al. (2011) used DTT to successfully teach perspective-taking to elementary students. While DTT can be utilized with all age groups, there are limited studies on its effectiveness for those 12 years and older.
The main objective of DTT is the acquisition of skills or behaviors. The types of skills that can be learned through this method include social skills, communication skills, school readiness, joint attention, adaptive skills, and academic skills.
Is Discrete Trial Training ABA Therapy?
DTT and ABA are different. ABA is a more comprehensive way to understand and modify behavior that includes a variety of strategies and techniques. DTT is a teaching technique within the framework of ABA.
ABA is based on the science of learning and behavior. It helps us to understand how behavior works, how behavior is affected by the environment, and how learning takes place. ABA therapy applies this understanding to improve socially significant behaviors. It can be used to teach new skills, reduce behaviors that are harmful or impact learning, and enhance the quality of life for those impacted with developmental disabilities and behavioral challenges.
Alternatively, DTT is a specific instructional method within the realm of ABA used to teach new skills. It involves breaking down complex skills into smaller components to teach them in simplified and structured steps. It’s conducted in an environment controlled by the therapist, that limits distractions and promotes focus, such as being seated at a table.
While DTT is a frequent component of ABA-based programs, ABA itself encompasses a broader set of principles and interventions beyond DTT. ABA is flexible, can be conducted in group settings, can be child-led, and can be implemented in multiple environments. For example, naturalistic teaching is a child-led ABA technique that occurs in the natural environment by incorporating learning opportunities into everyday life.
What are The Benefits of DTT?
According to Smith (2001), children with Autism can have different learning styles compared to their neurotypical peers. DTT can help children with ASD increase motivation and learning due to short trials, 1:1 distraction-free settings, and simple instructions clearly expressed. Since DTT uses prompts and error correction, it maximizes a child’s success and minimizes their failures (Smith, 2001).
Skills taught using DTT range from very simple to complex. The following are some areas where DTT can be beneficial for children with ASD:
- Communication skills – DTT can help to improve expressive language, such as increasing vocabulary or receptive language, for example, following instructions to put something away.
- Social skills – DTT can target several social skills, such as sharing, turn-taking, asking a friend to play, or responding to various social cues. For example, a child can be taught how to greet someone they know.
- Academic skills – DTT can be used to teach academic skills, such as letter recognition, number recognition, discriminating colors or shapes, and handwriting.
- Self-Help Skills – DTT can break down the steps involved in dressing, grooming, and basic hygiene into smaller, more teachable components.
- Play skills – DTT can teach sharing, turn-taking, engagement with toys, and how to initiate and sustain interactions with peers.
- Motor skills – DTT can be used to help develop fine and gross motor skills, like cutting with scissors, fastening buttons, and other motor-related tasks.
- Daily living skills – DTT can be used to help enhance the quality of life of a child by teaching skills, such as how to complete toileting independently, or how to make a sandwich.
- New behaviors – DTT is often used to address challenging behaviors by teaching alternative responses. For example, a child who frequently shouts answers in class can be taught to raise their hand.
Throughout my practice as a BCBA, I used DTT to teach a variety of skills. For example, I taught a 5-year-old child with ASD how to independently wash his hands. I first conducted a task analysis for hand washing, breaking it down into 9 simple steps, taught in order. I also created a visual chart that outlined the steps and placed it by the sink.
The instruction “Wash your hands” was given, and a prompt was provided to him by pointing to the first picture on the chart and the physical tap. The child turned on the tap and received reinforcement in the form of a high five. The step was repeated for several trials. Data was collected for each trial, with mastery being three consecutive trials of independently turning on the tap.
Once this step was mastered, we moved to the next step until each step in the task analysis was performed at mastery. The steps were then combined to be performed in sequence. The final step was to generalize, which involved teaching the child to use various types of taps, multiple soap dispensers, and hand-drying methods.
Key Principles of DTT
DTT implementation is guided by several key principles, including:
- Structured Learning – Each trial has a very specific set of clearly defined, predictable, and scripted steps. It is important to follow them as outlined because it allows program supervisors to easily identify effective strategies. Each trial has 5 steps:
a) Initial instruction – such as telling the child to clap their hands.
b) Prompt – assisting the child to comply with the instruction, such as using hand-over-hand guidance.
c) Child’s response – the child’s action of clapping their hands.
d) Consequence – either reinforcement or error correction.
e) Pause for rehearsal – a 1-5 second pause is typical between trials.
- Task Analysis – DTT is defined as breaking complex tasks into simpler, teachable steps. This process is known as a task analysis, which involves deconstructing behaviors into individual steps. This is an important process that creates the outline for skills to be taught.
- Reinforcement – This is a crucial aspect of DTT because it motivates the child to participate in the trials. After each trial, the child is reinforced with either a tangible item, such as a toy, praise (e.g., verbally saying “great work”), an edible item (e.g., a gummy bear), or sensory items (e.g., swinging or textured paper). This type of reinforcement is known as positive reinforcement, which is a consequence that increases the likelihood of the behavior occurring in the future. DTT also uses differential reinforcement, which provides positive reinforcement for a correct response, and no consequence or punishment, such as a reprimand or the removal of a preferred item, for an incorrect or inappropriate response. This form of reinforcement has the dual effect of increasing helpful behaviors and reducing harmful behaviors or behaviors that impact learning.
- Prompting – Prompting is a supplementary teaching aid used to help the child produce correct responses. There are several types of prompts, such as verbal, visual, physical (hand-over-hand), or gestural cues. Prompts help to ensure an errorless learning atmosphere. Helping the child to perform the correct response makes it less likely that they will perform an incorrect response. Errorless learning allows for more frequent reinforcement which maintains engagement.
- Prompt fading – Prompts gradually fade as the child becomes more independent. Typically, a prompt hierarchy is established before a DTT program is implemented. The therapist should begin with the least intrusive prompt that provides a correct response to aid in prompt fading. For example, gestural cues are considered less intrusive than hand-over-hand guidance.
How is DTT Performed?
DTT is a highly structured teaching technique that takes place in a carefully crafted learning environment. The different factors that come together to create a DTT session are outlined below.
Setting Up DTT Sessions
DTT typically takes place in a 1:1 clinical or school setting with the child and therapist sitting across from each other at a table or on the floor. The location should be relatively quiet and distraction-free. The child should not be able to freely access preferred items and activities.
DTT sessions should be fast-paced with minimal breaks between trials. Therapists must have all the material needed in place before the session begins. The material needed depends on what skills are being taught, for example, if you are teaching a child the colors red and yellow, the therapist should have red and yellow items within reach.
Most importantly, therapists must ensure they have preferred items or activities to use as reinforcement. These items should be identified before the DTT session begins and there should only be 2 to 3 items. It is important to note that preferences can change daily and the items and activities should not be the same each time.
All ABA-based programs begin with an assessment, including DTT. There are a variety of assessments used in designing DT programs, such as ABLLS-R, VP_MAPP, and the student learning profile from the STAR curriculum. The assessments are conducted by a certified professional, such as a BCBA, who works with family members and teachers to establish goals. The assessment results are used to break large goals down into smaller components to be taught step-by-step.
This assessment process ensures individualization by designing programs around the child’s strengths and weaknesses. For example, two clients can have the goal of telling their parents what they did at school. When this goal is broken down to meet each child’s needs, one child could be working on labeling locations and activities, while the other child may be working towards using adjectives to provide greater description.
BCBAs will also conduct preference assessments to determine items and activities to be used for the child’s reinforcement. Each child will have different preferred items that are developmentally appropriate for their age. It is important to not assume that an item will be reinforcing based on general societal norms. For example, most children respond positively to verbal praise, however, some children find the social attention drawn by praise to be aversive. Preference assessments are critical because if the item offered as a reinforcer does not motivate the child, it is not a true reinforcer.
Data Collection and Analysis
Informed, accurate data strengthens the effectiveness of DTT because BCBAs and other professionals can immediately see when a child has mastered a skill and is ready for a treatment change. Conversely, data analysis can help identify problems within a program. For example, if a child fails to produce the correct response five trials in a row, the BCBA can adjust by redefining a target skill or teaching prerequisite skills. Without ongoing data analysis, a child’s progress can be slowed due to the inability to accurately determine the child’s level.
The way therapists collect data during a session varies, but all collect data to show whether the response was correct or incorrect, performed with or without prompts, and the level of the prompt used to achieve the response.
Data collection choices range from manual to electronic, with some therapists prioritizing data collection and others aiming to minimize disruptions during the session. Those prioritizing data collection use a continuous recording with the therapist recording every trial, while those aiming to minimize disruptions use discontinuous recording with the therapist recording sample instructional trials. Continuous recording is more sensitive to changes in performance but less efficient than discontinuous recording.
Therapists also record either specific responses or nonspecific responses. Specific responses can be more time-consuming, but the data yielded more accurately reflects the child’s performance. Those using unspecific responses typically use a symbol to represent correct vs. incorrect and prompt vs. no prompt.
How Long Should DTT Last?
DTT can be very time-intensive, involving many hours a day for several years depending on the specific goals of the child. Intensive DTT sessions are typically scheduled for 5-7 days per week, for 6-8 hours per day. DTT can be scheduled for a duration of 6 months-3 years.
Challenges and Criticisms of DTT
Most criticism regarding ABA concerns DTT, its implementation, and the type of responses it can yield.
A key concern about DTT is the ability of the child to generalize the skills taught to more natural settings. DTT is scripted and can result in rote responses from children who go through the treatment approach. In addition, some children will only use the learned responses in the DTT session.
Modern ABA practitioners combine DTT with other naturalistic teaching methods, such as natural environment teaching (NET) and pivotal response treatment (PRT), to create opportunities in everyday life to use the skills learned during DTT. Combining these methods reduces the likelihood of rote responding.
The setting, stimuli, and instructors are also varied throughout the DTT process. For example, when teaching a child toileting skill, different types of toilets and flush handles are presented to ensure generalization of the skill learned to apply in multiple settings.
DTT involves a high number of repetitive trials in a short period, which can help with skill acquisition and allow for frequent reinforcement. However, modern ABA therapists have developed strategies to balance this within DTT sessions. For example, short breaks can be implemented to prevent fatigue and to keep motivation high. Therapists can introduce novel material or activities to add variety to the session. For example, when teaching colors, the therapist can use Lego blocks that the child can stack instead of using color cards. Lastly, targets can be rotated to avoid cycling through the same instructions each session.
Cultural and Ethical Considerations
Due to the therapist-initiated scripted nature of DTT, critics are concerned about the ethical and cultural implications of the process. For example, DTT can impact an individual’s autonomy and their right to make choices about their learning and participation. Values also vary across cultures, for example, not all cultures value making eye contact. To address these concerns, current practices in ABA and DTT focus less on encouraging sustained eye contact, and more upon orienting towards a speaker to convey attention.
Caregivers must give informed consent. The teaching technique should be explained to the caregiver, including its disadvantages and how they will be mitigated. In addition, caregivers should collaborate with professionals during the development of treatment plans to ensure their values, beliefs, and the child’s preferences are respected.
Future Directions and Innovations in DTT
Advances in Technology
Advances in technology have changed the way some DTT programs are implemented. Many digital platforms, apps, and virtual learning environments have been created, including interactive software, video modeling, and data collection apps designed to enhance the learning experience.
Technology results in more interactive and visually appealing content easily tailored to the child’s learning style, increasing the child’s engagement with the material. These digital tools allow for more efficient and accurate data collection for real-time analysis.
However, there is the risk of technological issues that can impact the smooth delivery of the trials, such as power outages or program glitches. Furthermore, the online platform can be seen as neglecting the importance of face-to-face personalized human interaction.
Implementing DTT cannot be limited to therapy sessions alone. There must be supportive strategies in place at home, schools, and other therapies. Consistency across all environments will help the child generalize skills learned during DTT to real-life situations.
Effective collaboration requires clear communication among all caregivers, teachers, and therapists. It is important to overcome communication barriers to create and implement cohesive treatment plans.
Research and Development
Ongoing research is essential to the refinement and expansion of DTT. Recent studies focused on improving teaching methods and increasing the individualization of interventions.
Advances in technology and artificial intelligence could create personalized learning algorithms that can dynamically adapt DTT programs based on the child’s progress and objectives. This combined with neuroscientific research that provides the basis of learning in children with developmental disorders could lead to more targeted and effective DTT interventions.
Frequently Asked Questions
Is DTT Evidence-Based?
Yes, DTT is an evidence-based teaching technique within the field of ABA. There is a considerable amount of research showing the effectiveness of DTT in teaching skills to children with developmental disorders spanning over four decades.
For What Age is Discrete Trial Training Designed?
DTT was designed to be implemented with young children between the ages of 2 and 6 years old. However, studies have shown that it is effective with children up to the age of 11 years old.
Is DTT a Naturalistic Training Method?
No, DTT is considered a highly structured and therapist-controlled teaching method. It is considered “unnatural” due to the repetitive nature of the technique, the contrived situations to enhance learning opportunities, and because the environment is highly structured to minimize distractions.
Can Discrete Trial Training be Conducted Outside, in a Community, or Home Setting?
Yes, DTT can be conducted in any setting – outside, in the community, or at home. DTT is typically used in a clinical or school setting, however, it can be conducted in any environment that has minimal distractions and does not allow for free access to preferred activities or tangible items.
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Sam, A., & AFIRM Team. (2016). Discrete Trial Training. Chapel Hill, NC: National Professional Development Center on Autism Spectrum Disorder, FPG Child Development Center, University of North Carolina. Retrieved from: http://afirm.fpg.unc.edu/discrete-trial-training.