Skip to content

How to Do a Functional Behavior Assessment in ABA: A Comprehensive Guide


Imagine you’re presented with two children: both prone to biting. On the surface, it seems like they’re exhibiting the same behavior, but delve a little deeper and a different picture starts to emerge — one child bites for attention, the other for escape.

How do we decipher this crucial difference? Welcome to the world of Functional Behavior Assessment in ABA.

A Functional Behavior Assessment (FBA) plays a crucial role in understanding and addressing challenging behaviors. It provides valuable insights into the underlying causes of these behaviors, allowing educators, parents, and professionals to develop effective behavior intervention strategies.

Often, when faced with a behavioral challenge, we’re inclined to seek quick fixes. However, in ABA, our mantra is, “It depends.” Why? Because effective behavior management isn’t about merely addressing what the behavior looks like, but understanding the function it serves.

In this comprehensive guide, we’ll give you the knowledge and tools to conduct an FBA – the gold standard in function-based intervention. Rather than taking a guess, learn how to unravel the complexities behind behaviors and choose interventions that hit the mark every time.

What is a Functional Behavior Assessment?

To start, let’s establish the foundation of what an FBA entails. A Functional Behavior Assessment is a systematic process that involves gathering and analyzing data to determine the function or purpose of a specific behavior. This assessment helps identify the reasons behind challenging behaviors and allows for the development of appropriate interventions.

It’s crucial to differentiate between descriptive assessments, which focus on describing the behavior, and functional assessments, which strive to understand the purpose of the behavior. By conducting an FBA, we move beyond surface-level observations and gain deeper insights into the motivating factors behind the behavior.

We hope to get enough answers from a functional assessment (FBA) so that we don’t have to move towards a functional analysis (FA) – an intentional manipulation of the variables in a contrived setting in order to turn on and off the behavior in question. A functional analysis poses many risks and downsides and should not be the first approach in determining the function of behavior.

Who Should Conduct a Functional Behavior Assessment?

A functional behavior assessment should be conducted by a BCBA or BCBA-D. The team can assist in the process, especially with the data collection, but it should all be under the supervision and guidance of the BCBA.

Want more on writing an ABA behavior plan? There’s an entire video training on the topic, including downloadable behavior plan templates…all in The Bx Resource!

Preparing for a Functional Behavior Assessment

Before conducting an FBA, it is essential to prepare properly. This preparation involves gathering relevant information about the individual’s behavior — such as behavioral history, triggers, environmental factors, and any previous interventions attempted.

Additionally, it’s essential to identify key stakeholders involved in the assessment process, including educators, parents, therapists, and other professionals who work closely with the individual.

The solution to promoting positive behavior strategies lies in figuring out what the behavior is trying to say.  It can be communicating one of four main functions (or multiple functions at once): Sensory, Escape Attention, Tangible (SEAT).Please note, the function of challenging behavior is not always limited to these functions, but behaviorists like to simplify things! Once we know the function,, we can apply a function-based intervention with replacement skills that is more likely to be effective.

Disclaimer: Always rule out any physiological/medical reason or any other change in the child’s life before beginning a behavior intervention.


How to Conduct a Functional Behavior Assessment

The process of conducting a Functional Behavior Assessment can be broken down into several steps:

1. Collect Data: Uncover the Behavior in Question

Start by collecting data through direct observation and interviews with individuals involved in the learner’s life. This information provides a comprehensive understanding of the behavior in different contexts.

Ultimately, your goal is to identify and define the behavior that’s causing concern. Consider:

  • Does the behavior obstruct learning?
  • Compromise safety?
  • Lead to social isolation or decreased independence?

If you answered, “Yes” to any of these, then it’s time to keenly observe and describe the behavior in measurable terms. For instance, instead of labeling it as, “Head-banging”, we might specify it as, “Any instance when the forehead makes contact with an object, floor or wall.”

2. Gather Baseline Data

This step involves accumulating a wealth of information to form a solid foundation for your hypothesis. Consider employing various data collection methods such as:

  • Antecedents, Behaviors & Consequences (ABC Data): Carefully analyze the relationship between antecedents (events or situations preceding the behavior), the behavior itself, and the consequences (what happens immediately after the behavior). This analysis helps identify potential patterns and triggers.
  • Direct observation: While in-person observation is ideal, it’s not always possible due to the unpredictable nature of the behavior. In such cases, video recording can be a useful tool.
  • Screening tools: Questionnaires and interviews are valuable tools for gathering information for behavior assessment.Short-answer questionnaires, such as the Motivation Assessment Scale (MAS) and the Functional Analysis Screening Tool (FAST), provide a structured approach to capturing essential data about an individual’s motivations and behavioral patterns. These questionnaires offer a quick and efficient way to gather information from multiple sources, including caregivers, educators, and parents. The Open Ended Functional Assessment (Hanley) is a more recent approach that allows for a deeper exploration of the underlying functions of behavior through open-ended questions and qualitative analysis. This method encourages a more comprehensive understanding of behavior and provides valuable insights for developing effective intervention strategies. It especially aims to conduct a quick, comprehensive assessment through pointed questions that would give us information on synthesized contingencies (eg: a child who leaves work to go play is motivated by both escape and access).

Want more on writing an ABA behavior plan? There’s an entire video training on the topic, including downloadable behavior plan templates…all in The Bx Resource!

3. Develop a Hypothesis

Based on the data collected, develop a hypothesis about the function or purpose of the behavior. This hypothesis serves as a working theory that guides further investigation:

  • Is the behavior constantly occurring when the child is given a demand?
  • Are there other setting events (e.g., didn’t sleep well at night)?
  • What kinds of consequences is the child receiving?

4. Test the Hypothesis

If the function isn’t clear after the first three steps, a functional analysis might be required. This involves intentionally evoking and reinforcing the behavior to determine its function. However, this method carries certain risks and should only be conducted by an experienced BCBA.

5. Collect Additional Data

If necessary, collect additional data to either support or challenge the initial hypothesis. This continuous data collection ensures a comprehensive understanding of the behavior.

Then, refine and update the hypothesis based on new findings and insights gained throughout the Functional Behavior Assessment process.


6. Analyze Data & Develop a Plan

Once sufficient data has been collected, it’s time to analyze and interpret the findings. Organize and summarize the collected data, looking for patterns, trends, and correlations between different variables. By analyzing the data, you can gain valuable insights into the function of the behavior and identify the underlying causes.

  • Developing Effective Behavior Strategies: The results of the FBA serve as a foundation for developing individualized behavior intervention strategies.Utilize the identified function of the behavior to guide the selection of appropriate interventions and supports. Collaborate with key family members and ABA professionals to ensure a holistic approach to addressing the behavior.
  • Evaluating The Effectiveness Of The Behavior Plan: Monitoring and evaluating the effectiveness of the behavior plan is vital for promoting positive behavior change for the learner.

Continuously track progress toward behavior goals and make necessary adjustments based on ongoing data collection. And don’t forget to celebrate successes and recognize areas for further improvement.

A Functional Behavior Assessment (FBA) is a powerful tool for understanding and addressing challenging behaviors. By conducting an FBA, educators, parents, and ABA professionals can gain valuable insights into the underlying causes of these behaviors and develop effective behavior intervention strategies.

The process outlined in this post provides a comprehensive guide to conducting an FBA and highlights its significance in promoting positive behavior change. Utilize the power of functional behavior assessments to support individuals in achieving their full potential.

Want more on writing an ABA behavior plan? There’s an entire video training on the topic, including downloadable behavior plan templates…all in The Bx Resource!

4 thoughts on “How to Do a Functional Behavior Assessment in ABA: A Comprehensive Guide”

  1. That’s definitely important to consider. It all depends on the situation and what’s functional. Does the person want to help manage the fear and be able to tolerate group situations? Is the fear getting in the way of other important life activities? If it’s manageable then it’s not something to target. There are a lot of factors to look at before intervening and we wouldn’t recommend putting anyone in an uncomfortable position without a positive support plan and a strong reason for doing so.

  2. Pingback: Writing a Behaviour Intervention Plan (BIP) - How to ABA

Leave a Reply

Your email address will not be published. Required fields are marked *

Captcha loading...