Discrete trial training is a type of training based on applied behavior analysis (ABA). The goal is to help clients with autism learn how to appropriately respond to situations. This can improve relationships, enhance communication, and boost overall quality of life.

The ABCs of Behavior

Discrete trial training uses what PsychCentral calls “the ABCs of behavior”: antecedent-behavior-consequence.

The ABCs are a fundamental component of how applied behavior analysis therapy works. In this theory, behavior is a three-step process: first, the antecedent (the cue, the prompt, or the instruction); second, the behavior itself; and third, the consequence (here, consequence means “result,” to distinguish from the typical negative connotation).

A simple example is eating. The state of being hungry is the antecedent; eating something is the behavior; feeling satisfied or full is the consequence. This is what a registered behavior technician would call a positive consequence for the behavior, and it increases the likelihood that a person will naturally repeat these steps when they are hungry in the future — perhaps not even thinking of the process of hunger-eating-satisfaction in terms of antecedent-behavior-response.

In applied behavior analysis, this principle is used to induce and encourage positive changes in behavior. It is commonly used in autism therapy, but it’s also used in other disciplines to help clients develop desired behavior — anything from lifestyle changes to curbing harmful impulses.

It is the basis of human behavior. Rewards or consequences can make certain behaviors more or less likely to recur in the future.

The paradigm of antecedent-behavior-consequence happens for millions of people every day. However, for children who are on the autism spectrum, developing this pattern of understanding, and then applying it in social situations, either does not happen at all or happens only in a very limited and minimal form.

Discrete Trial Training in ABA

Discrete trial training (DTT) breaks down behaviors for clients into small, discrete blocks (or components) and reinforces those behaviors with specific methods and sequences. The goal is to build up to a single, overall, desired behavior.

When a number of different skills are linked together in this way, the process is known as chaining.

Each child who is on the autism spectrum will have their own version of a complex behavior that needs to be broken down. This can be anything, such as getting through a full day from sunrise to sunset, or even a single activity like taking a bath, without having a meltdown.

Parents and caregivers are faced with the challenge of reinforcing every little victory in order to achieve a final positive outcome. The more steps a behavior requires, the harder it is to wait for the final step to provide a reward because that system will not reinforce immediate steps. It will also not provide a suitable way of correcting any inappropriate behaviors that occur during the process.

This is where discrete trial training can help. DTT gives registered behavior technicians a clinical way they can isolate and reinforce behaviors that have complicated antecedents or consequences (for example, how to behave in a social setting with particular rules). There are many cues that neurotypical people take for granted or might not even notice in any given social situation. Those with some form of autism spectrum disorder will likely have to clear a number of challenges covering everything from noise levels to behavior, from acting in a way that is expected of them in that situation to knowing what to do next.

What discrete trial training does is break all the steps down into individual pieces, each one thoroughly described and practiced, with the RBT offering clear and straightforward instruction at every turn. The last step of DTT is to put all these steps back together (chaining them), which will form the complete sequence of events that will comprise the social situation the client is struggling with.

How Does Discrete Trial Training Work?

Every discrete trial training process has five steps:

  1. Antecedent
  2. Prompt
  3. Response
  4. Consequence (correct or incorrect) for the response
  5. Interval between trials

Discrete trial training is also used for situations where the behavior might not appear to be complex, but where other methods of applied behavior analysis might not be able to help a client adopt such behaviors. For example, clients with low-functioning presentations of autism could benefit from DTT in developing behaviors as seemingly simple as asking another person if they can share a toy. A discrete trial could be as meticulous and as granular as learning the sounds of each individual word to phrase the request, or conceptualizing the concepts of making the request and then engaging in mutual playtime.

In a discrete trial training session, the therapist will give prompts to the client, which are specifically designed to bring out appropriate behavioral responses. When the client offers the correct response, they receive a reward to positively reinforce that behavior. This reward could be praise, candy, or getting the opportunity to color, play with a toy, or watch a cartoon for a short time. When the child offers an inappropriate response, the RBT will respond with a gentle correction and try the prompt again.

This process is intended to shape the responses, giving the client guidance to see the prompts as part of a process of proper behavioral patterns, and not simply random cues and antecedents. With the structure offered by discrete trial training, many children will learn how to control their behavior by themselves.

Prompting in DTT

In discrete trial training, prompts come in different forms. One example is known as a full gestural prompt, where the therapist will offer a verbal cue — such as “point to blue,” meaning point to the blue item on the table — and then immediately point to the item themselves. This effectively tells the client what to do, but it models the behavior that leads to the reinforcement.

When the client understands how this works, the therapist can use another kind of prompt. This could be a partial gestural prompt. After saying “point to blue,” the therapist only partially indicates the blue item. Because the therapist has modeled the desired skill, and there is the expectation of reinforcement, the client should know to completely point at the blue item and accordingly receive the reward.

This can continue to the point where no prompt is necessary. The client knows to select the correct item from the table based on nothing more than the verbal cue offered by the therapist. 

Intensive Therapy

Discrete trial training is very successful, and it has been a big driver in the success of applied behavior analysis for helping children on the autism spectrum. However, it is a lot of work.

DTT is an intensive therapy regimen, and it can be very time consuming. Even under ideal circumstances, DTT sessions would be scheduled five days a week, lasting up to 40 hours in total, as a registered behavior technician works with a client on every minute step of the interaction and situation that needs to be conceptualized.

The work of discrete trial therapy can be very slow and sometimes frustrating. Much of it involves basic repetition until the desired skills are learned and demonstrated. It is the therapist’s responsibility to move ahead with new skills at whatever pace the client can manage, no matter how long it takes. A good registered behavior technician will also know how to recognize when a client is losing focus, so they can try another approach or temporarily pause the session.

Another way discrete trial training can work is when the therapist teaches colors to a client. If the color is red, for example, the therapist asks the child to point to an object that is red in color, and then rewards the child for correctly identifying it. The therapist might then move on to working with the color yellow, and when the client has mastered antecedent-behavior-consequence with that color, combine the exercise with red and yellow items, to help the client discriminate between the two. This will be important to help the client understand real-world situations, such as safety signs that are red or warning signs that are bright yellow. 


Discrete trials are very carefully designed to ensure that every trial is run in the same way. If a step in the process doesn’t work, the identical nature of the trial allows a therapist to identify the problem and change the approach slightly.

An example of this is in how reinforcement is offered. If one therapist used a full gestural prompt while another therapist used a partial gestural prompt, the client might find the concept of consequences difficult to process, and they might not master the skill being taught in the trial. Having different gestural prompts also makes it difficult to tell which prompt is working better.

Standardizing the discrete trials across every stage of the process allows ABA practitioners to change and individualize their programs as much as necessary to be most effective for their clients.

DTT & Learning

Children who have some form of autism spectrum disorder exhibit a disinterest in learning new things. This level of interest tends to develop more naturally in their neurotypical peers.

Children with autism will often struggle to learn by observing others or exploring their environments and surroundings. They will not be able to easily communicate, play, or otherwise engage with others.

This is where discrete trial training comes in. It is designed specifically to increase the motivation for learning for a child who has autism. Each trial is short, allowing for a number of trials to be completed and learning opportunities to be imparted before the child needs to take a break.

The one-to-one method of DTT creates the opportunity for the program to be completely individualized to the needs of every client. Therapists can tailor the program as the client grows. Since there is no one-size-fits-all approach that works for everyone, discrete trial training allows the therapist to truly customize the practice to what works best for the individual client.

The fact that DTT is so procedurally oriented creates a sense of clarity for the client, so it works within the constructs of their autistic abilities. Every trial has a clear start and conclusion, with prompts and antecedents kept to an accessible and appropriate level.

The Success of Discrete Trial Training

In separating tasks into discrete trials, discrete trial therapy not only maximizes the successes of clients who receive the therapy; it minimizes their failures. It helps clients to develop strong learning and association skills that they can use for the rest of their lives.