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Behaviour Analysis is the science of behaviour. Applied behaviour analysis (ABA) is the process of systematically applying interventions, based upon the principles of learning theory, to improve socially significant behaviours to a meaningful degree.

The Applied Behaviour Analysis (ABA) approach teaches social, motor, and verbal behaviours, as well as reasoning skills. ABA treatment is especially useful in teaching behaviours to children with autism who may otherwise not “pick up” these behaviours on their own, as other children would. The ABA approach can be used by a parent, counselor, or certified behaviour analyst.

ABA uses careful behavioural observation and positive reinforcement or prompting to teach each step of a behaviour. A child’s behaviour is reinforced with a reward when he or she performs each of the steps correctly. Undesirable behaviours, or those that interfere with learning and social skills, are watched closely. The goal is to determine what happens to trigger a behaviour, and what happens after that behaviour to reinforce it. The idea is to remove these triggers and reinforcers from the child’s environment. New reinforcers are then used to teach the child a different behaviour in response to the same trigger.

ABA treatment can include any of several established teaching tools, including discrete trial training, incidental teaching, pivotal response training, fluency building, and verbal behaviour (VB).

In discrete trial training, an ABA practitioner gives a clear instruction about a desired behaviour (e.g. “Pick up the paper”). If the child responds correctly, the behaviour is reinforced (e.g. “Great job! Have an M&M”). If the child doesn’t respond correctly, the practitioner gives a gentle prompt (e.g. places child’s hand over the paper). The hope is that the child will eventually learn to generalize the correct response.

Incidental teaching uses the same ideas as discrete trial training, except the goal is to teach behaviours and concepts throughout a child’s day-to-day experience.

Pivotal response training (PRT) uses ABA techniques to target crucial skills that are important (or pivotal) for many other skills. Thus, if the child improves on one of these pivotal skills, improvements are seen in a wide variety of behaviours that were not specifically trained. The idea is that this approach can help the child generalize behaviours from a therapy setting to everyday settings.

In fluency building, the practitioner uses the ABA approach to help the child build up to a complex behaviour by teaching each element of that behaviour until it is automatic or “fluent”. Then, the more complex behaviour can be built from each of these fluent elements.

Finally, an ABA-related approach for teaching language and communication is called verbal behaviour (VB). In VB, the practitioner analyzes the child’s language skills, then teaches and reinforces more useful and complex language skills.

Through ABA training, parents and other caretakers can learn to see the natural triggers and reinforcers in the child’s environment. For example, by keeping a chart of the times and events both before and after Michael’s tantrums, a parent might discover that Michael always throws a tantrum right after the lights go on at night without warning. Looking deeper at the behaviour, Michael’s mother might also notice that her most natural response is to cuddle Michael in order to get him to calm down. In effect, even though she is doing something completely natural, the cuddling is reinforcing Michael’s tantrum. According to the ABA approach, both the trigger (lights going on at night without a warning) and the reinforcer (cuddling) must be stopped. Then a more appropriate set of behaviours (like leaving the room or dimming the lights) can be taught to Michael, each one being reinforced or prompted as needed. Eventually, the hope is that this kind of approach will lead to a time when the lights can go on without warning and Michael will not throw a tantrum.

Many experts believe that children with autism are less likely than other children to learn from the everyday environment. The ABA approach attempts to fill this gap by providing teaching tools that focus on simplified instructional steps and consistent reinforcement. At best, the ABA approach can help children with autism lead more independent and socially active lives. Research suggests that this positive outcome is more common for children who have received early intervention. This may be due to critical brain development that occurs during the preschool years and can be affected by training.

ABA is considered by many researchers and clinicians to be the most effective evidence-based therapeutic approach demonstrated thus far for children with autism. The U.S. Surgeon General states that thirty years of research on the ABA approach has shown very positive outcomes when ABA is used as an early-intervention tool for autism. This research includes several landmark studies showing that about 50% of children with autism who were treated with the ABA approach before the age of four had significant increases in IQ, verbal ability, and/or social functioning. Even those who did not show these dramatic improvements had significantly better improvement than matched children in the control groups. In addition, some children who received ABA therapy were eventually able to attend classes with their peers. A similar study in older children showed improvements in behaviour but not in IQ. Studies of parental satisfaction with ABA indicate that parents believe the approach is effective. Parents also report that they experience less stress as a result of applying ABA.

There are, however, some controversies surrounding the ABA approach. Early ABA practice (in the 1980’s and early 1990’s) included the use of aversive techniques such as yelling at or restraining a child. Most ABA practitioners no longer consider aversive techniques to be acceptable, and the current ABA approach is equally effective without these techniques.

Experts also disagree as to whether the ABA approach should be used alone or in addition to other treatment methods. While there are varied opinions, most practitioners agree upon the importance of early intervention, intensive treatment for as much time as possible each day (in the range of 25 to 40 hours per week), well-trained practitioners, and consistent application of the ABA approach within and outside of school.

A crucial element of the ABA approach that is especially important for children with autism is finding appropriate reinforcement for each child. Because praise may not be rewarding for these children, careful analysis of each child’s behaviour can help reveal more effective reinforcement tools. Examples of successful reinforcers may include access to a favorite toy or chair.

There are no known negative effects of the ABA approach. This is especially the case if gentle prompting is used rather than aversive techniques.


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By Lara Pullen, PhD. The information from this page was reprinted with permission from Healing Thresholds. “Copyright (c) 2007, Healing Thresholds, Inc. All rights reserved”


Autism Canada does not endorse treatments, interventions and therapies but lists them so people can make informed choice.  This site is for information purposes only and is a starting point for readers to look into options that may fit or resonate.  Remember, therapies for autism, like any condition, should be discussed with a trusted medical practitioner or certified therapist before use.

All information, data and material contained, presented or provided here is for general information purposes only and is not to be construed as reflecting the knowledge or opinions of Autism Canada, or as providing legal or medical advice. All treatment decisions should be made by the individual in consultation with a licensed health care provider.

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