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What is Functional Behavior Analysis?

September 28, 2023

Functional behavior analysis can be used in special education or in Applied Behavior Analysis, also known as ABA, to allow the observer to learn what triggers and leads to challenging behaviors. This type of intervention helps us learn the function of difficult behaviors as well as environmental factors that may impact or interfere with Behavior Intervention Plans (BIP), Individualized Education Plans (IEP), or other programs that are put in place to support positive behaviors. Without an evaluation of direct and indirect factors that affect the students, conducting assessments or data collection would not properly identify the functions of behaviors that occur.

What is Functional Behavior Analysis?

Understanding Functional Behavior Analysis

Functional behavior analysis allows professionals to have direct observation of problem behaviors so that a behavior intervention plan can be planned to help target behavior that is negative and introduce replacement behaviors that are more functional and appropriate. 

Parents and teachers can do informal assessments when a behavior occurs to help determine why a child is engaging in specific behaviors and develop supports and a plan to help address the situation that may be happening in the school, in class, or in the home.  

“In the cognitive-behavioral approach, Functional Behavioural Assessment is one of the most effective methods to identify the variables that determine a problem behavior” (Merlo, et al., 2018). 

These insights could help parents target behavior that is problematic and provide appropriate behavioral interventions in school and at home so that the student is able to achieve success in school and other environments, as well as having a strong support team with resources to assist in the process of behavior change.

Components of Functional Behavior Assessment

Functional behavior assessment, also known as FBA, helps parents, teachers, and health care professionals identify why behaviors are happening. Individuals with disabilities may not always have the ability to speak up for themselves and be a self advocate when something in their environment is bothersome. Negative behaviors often act as a nonverbal way of communicating that something is not right in a child’s environment. Sometimes, observation can help us see a different perspective we might not have noticed before. 

For example, if a child is constantly trying to leave the classroom or engage in inappropriate behaviors during math class, a teacher without knowledge of functional behavioral assessment might label the child disobedient, defiant, or disrespectful. Using functional behavior assessments, we can take a direct observation and a different perspective of the behaviors to understand that the function of these negative behaviors are avoidance and escape. The work may be too challenging for the student, causing anxiety and chronic levels of stress. A teacher using the methods of functional behavior assessment FBA could monitor when behavior occurs and keep track of data to create interventions that are specific to the needs of the child in the classroom. Breaking down the work into smaller steps, reducing the amount of work, or having a classroom aid work one-on-one with the student would help decrease avoidance and escape behaviors and the student will have a more positive educational experience in their program or school.

Observation and data collecting make up the functional behavioral assessment. Observation is observing any negative behaviors and making note of the situation, environmental factors, and possible triggers that could have an impact or influence on behaviors. Data collecting uses the ABA approach, known as ABC data, which stands for Antecedent, Behavior, and Consequences. Antecedent is what happens before the behavior starts. Behavior is the negative action that happens after the antecedent. Consequences are what happens as a result of the behaviors. 

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An example of FBA with ABC data could be noted during a thunderstorm at home. If a child is afraid of thunderstorms, the antecedent would be the thunder. The behaviors could be crying, repetitive rocking, or stimming with the functions of trying to soothe themselves as a result of the antecedent; the thunder. The consequence, or what happens after the behavior, could be extra cuddles from the parents with the attempt to comfort the child. Understanding the function of behaviors could help parents plan appropriately for the next time they know a thunderstorm will be happening.  

Using FBA, you now know what to expect when a thunderstorm starts, you can predict how the child will react and provide replacement behaviors. You can play music to drown out the sound of the thunder or take out special toys that are only used exclusively during this special time to make thunderstorms fun instead of scary. The consequence will adapt and change from comforting the child, to having fun with your child, and he/she may even start to look forward to thunderstorms!

Should your child with autism be analyzed or assessed?

If your child has repetitive behaviors that are problematic or challenging, having a functional behavior assessment done can help identify triggers that are causing his/her distress. This knowledge and the skills used in FBA can help with intervention and team efforts in changing and shaping target behaviors so that the new behaviors will be more appropriate and functional. The data used in the analysis of behaviors can help parents, teachers, and therapists determine the best type of intervention or program that fits the individualized needs of the child or student.

There are six steps that make up functional behavior assessments. Each of these steps are important because they are part of the process used to change maladaptive or problem behaviors.

The six steps that make up the FBA process are:

  • Choose and define the challenging behavior that you want to change or shape
  • Collect data on the problem behavior
  • Determine the “why” or function of the negative behavior
  • Conduct a functional behavior assessment
  • Write up a behavior intervention plan
  • Teach the child or student a replacement behavior that is more desirable or acceptable

When choosing a challenging behavior you want to change, choose only one to start with at a time. Trying to change too many behaviors at once could create unnecessary stress and anxiety to both the child and parents. Trying to tackle too many problems at once could also set the child up for failure and unknowingly add to the frequency and duration of maladaptive behaviors. You may even find that many of the challenging behaviors were connected to the same root cause, so changing one behavior could improve multiple behaviors at once. 

Collecting data on the problem behavior is important as well so that you are able to scientifically define if the intervention you are using is effective. You may also find that the problem behavior you wanted to change may have not been so problematic or happened as often as once thought in comparison to other behaviors.

Finding out why a behavior is happening, or the function of the behavior, is important because it helps you to understand the purpose  of why a student is engaging in, or communicating in, a specific manner. If a student acts out only during testing at school, you know that the student is trying to avoid having to take the test and different interventions that help with testing anxiety would be more appropriate and functional than disciplinary actions, because the problem is not disciplinary.

Conducting the functional behavior assessments allows you to observe and study the child or student’s environment and behaviors. This is where your ABC (Antecedent, Behavior, Consequence) data comes in handy. You’ll be able to notice triggers that may instigate behaviors and see how your child or student reacts to different situations. This step is crucial for writing your intervention plan.

Creating a behavior intervention plan and using it consistently will help you change behaviors over time. For example, if your child throws a temper tantrum at the store because he/she wants candy, ignoring the behavior and not giving attention or positive reinforcement to the child could be part of the behavior intervention plan. The child will learn after so many times of not getting your attention, that having a meltdown at the store over candy will not be rewarded and the function of the behavior, access to a desired item, becomes null and void. This is where implementation of the last step, or, replacement behaviors, come into play.

Replacement behaviors are what you want to replace a behavior with. You are teaching a child to change an old habit or negative behavior, into a positive or more appropriate behavior. In this example, a more appropriate behavior would be for the child to use words to communicate what he/she wants instead of having a meltdown would be more functional. You could prompt the child to ask: “May I pick out a piece of candy before we leave the store?” This more appropriate behavior can be understood by everyone and the child is able to communicate clearly.


Functional behavior analysis can help parents, teachers, and caregivers understand the function of negative behaviors and create appropriate behavior intervention programs that individually meet the needs of the child or student. 

Observation and data collecting are important components of FBA so that triggers can be identified and negative behaviors can be prevented. Through evaluation of the programs within FBA, we are able to grasp a better idea of how children are impacted by their environment and provide better support and resources to help them achieve success.


Merlo, G., Chiazzese, G., Taibi, D., & Chifari, A. (2018). Development and Validation of a Functional Behavioural Assessment Ontology to Support Behavioural Health Interventions. JMIR medical      informatics, 6(2), e37. https://doi.org/10.2196/medinform.7799.

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