While ABA stands for applied behavior analysis, the ABA and ABAB methods are not acronyms, but rather models of research. They are often used within applied behavior analysis (ABA) as a way to find out if specific interventions being used to modify behaviors are working.

Simply put, the ABA and ABAB designs are research methods that therapists can apply in ABA therapy to help evolve treatment plans and hone in on effective techniques. The A refers to the baseline and the B the intervention.

With ABAB, a therapist can see how well an intervention is working by removing it, returning to the baseline, and then reintroducing it. This can help single out the specific therapeutic method to check its impact. There are a few key differences between ABA and ABAB design and pros and cons to each, which we’ll cover below.

The ABA Design in Applied Behavior Analysis (ABA)

ABA therapy is a common treatment method for autism and involves positive reinforcement to modify problem behaviors. Typically, a trained professional will spend some time observing a child to determine their baseline — their typical way of functioning and handling things — first. With the ABA design, this baseline is the “A,” or unaltered behavior. 

The next component is to use an intervention to help modify the behavior. For instance, a child with autism often prefers a strict structure and schedule, and change can be difficult. A therapist can introduce methods — such as a task chart — to make transitions easier and, when the child complies, offer a reward. The behavior is then modified in a positive manner. The method used to change the behavior is the intervention — the B in the ABA design. 

The final A in the ABA design is removing the intervention, the B, which in this case is the task chart. The therapist will ask the child to transition to the next event with the aid of the intervention. This method can help to determine if the intervention, i.e., the task chart, is working the way it is intended to.

Adding in Reversal & Intervention ABAB Design

The ABAB design adds an additional component: the reintroduction of the intervention. This can help see if the desired behavior returns back to baseline and then improves a second time. So ABAB works as follows

  • A — baseline and initial assessment
  • B — intervention
  • A — removal of the intervention and a return to baseline
  • B — reintroduction of the intervention

The ABAB method is a research tool that has two main components: (1) an initial assessment and intervention to gather information on its effectiveness, and (2) measuring what happens when the treatment is stopped and then reapplied. Some level of extinction — a return to baseline without the intervention — is expected and anticipated.

In the case of behavioral intervention, this can include reintroducing the task chart to see if transitions are once again easier and more effective with the reapplication. The ABAB method can also be useful in finding out if the positive reinforcement being used to modify the behavior is working. 

For example, if the therapist uses extra time doing something the child enjoys as a positive reinforcement for the smooth transition during the second A — the withdrawal — this reinforcer is stopped to determine if the child will continue to transition easily without it. 

With the second B, the therapist adds back in the reinforcer. If the child responds positively, the therapist determines that the reinforcement is working to enhance behaviors.

Benefits of the ABA & ABAB Designs

The ABA and ABAB designs can help assess what methods and interventions are effective and which are less so. This is because only one thing at a time is changed and then studied. If the behavior returns to baseline without the intervention during the reversal phase, it can be inferred that the intervention works. If the behavior does not change with the withdrawal of the intervention and does not revert back to baseline, then there may be another factor impacting the change.

The ABA design can help find effective treatment methods and models. The ABAB method reintroduces the intervention to help end on a positive note as the therapy is brought back. By using specific controls and only one variable, it is possible to speed up learning and behavioral modifications with a better understanding of what works.

Potential Pitfalls

A downfall of the ABA and ABAB methods is that a person can spend more time in the assessment phase. It can take several applications of intervention and withdrawal during a reversal design to reach stable levels. 

It also can bring up ethical questions of removing a therapeutic technique from someone when it is actually working. Similarly, it can be tough to know if there are no additional variables at play and whether the intervention is effective on its own.

The ABA and ABAB designs can offer shorter treatment durations and a higher likelihood of success with specific interventions as these methods are closely monitored and assessed during each phase of the process. 

It can seem counterintuitive to withdraw a potentially effective treatment. But with ABAB, the intervention is brought back and is likely to work even more quickly the second time. This means behavior modification is likely to be even stronger than before. 

Both the ABA and ABAB methods can be used with a variety of therapies, ages, and cognitive ability levels.


What Is the A-B-A Design in Applied Behavior Analysis? Applied Behavior Analysis Programs Guide.

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Measurement, Experimental Design, Methodology. (2020). Functional Analysis.