Functional Behavioral Assessment: Overview for Parents

by Leslie E. Packer, PhD, 2004


When the U.S. federal law regulating special education was reauthorized in 1997, it revised the way schools were supposed to address disability-related problem behaviors. One of the new requirements was that school districts conduct a “Functional Behavioral Assessment” (FBA) to look at the relationship between behaviors that interfere with the child’s ability to learn and to then develop a plan that incorporated both positive behavioral interventions and supports. The purpose of this overview is to provide parents with some sense of what an FBA really is and its value in planning for their child and in developing interventions for their child.


Long before the federal regulations were changed, behaviorists were using applied behavioral analysis to study behavior and to develop and assess behavior interventions. In its most basic form, we talk about the “ABCs” of behavior analysis, where the acronym “ABC” stands for “Antecedent, Behavior, Consequences.” Behavior analysts look at what was going on before the behavior occurred (the antecedent conditions), what the behavior looked like (including its form and how long it lasted), and what happened after the behavior occurred (the responses of those in the environment, any consequences, etc.).

As with many things, conducting an ABC analysis of behavior may sound simple but be complex to do well. Those who are not trained in the field often do not know what is important to record about the antecedent conditions and may characterize behavior instead of describing it objectively. As we will see, the same problems may occur in an FBA.

If an ABC analysis is done correctly, with enough observations over days, you should get some sense of what conditions lead to or are correlated with the occurrence of the behavior and what consequences might be maintaining the behavior. Those hypotheses will lead to possible interventions.


Functional behavioral assessment goes beyond an ABC analysis of behavior. It is a multidisciplinary approach that incorporates a number of techniques, sources of information, and strategies to understand the causes of problem behavior and to develop strategies or interventions to address the problem behaviors. Unlike an ABC analysis that looks at immediate (or relatively immediate) antecedent conditions, an FBA also includes biological factors, social factors, emotional factors, and environmental factors that contribute to triggering, causing, maintaining, or ending the behavior.

Perhaps a simpler way to describe an FBA is to say that it is an approach oriented to understanding what function the behavior or symptom serves for the student so that it can be addressed. Both an ABA analysis and an FBA share certain requirements, not the least of which is that those involved start by providing a concrete objective definition of the problem behavior. For example, to say that Joey is “non-cooperative” is somewhat subjective. To say that “When asked to take his seat and start working, Joey does not comply with those directions” gives us a clearer sense.

What sources of information does an FBA include to lead to some hypothesis about the function of a particular behavior? There is no hard and fast rule, but let’s start by considering what type of information we need and then we can think about how to obtain the answers to these questions:

  • Does the behavior occur in all settings or just some?
  • Does the behavior occur frequently or infrequently?
  • Does the student have the necessary skills to engage in the desired behavior or is there a skills deficit that needs to be addressed?
  • Does the student understand the expectations for behavior?
  • What is the “payoff” is for the behavior — e.g., does the student get to avoid some unpleasant activity or get to escape some setting?
  • Does the student have the ability to control the behavior or will she need some supports to control it?
  • If the student does have the skills to perform the desired behavior, does the student have the motivation to perform it?

To answer the above questions, the school team will generally need to employ a variety of techniques. An FBA should not be based on one person’s report or observations. It really requires multiple participants and techniques. When it comes to techniques, in addition to direct assessment of the student and recording of behavior ABC-style, the team will probably also use:

  • Structured or semi-structured interviews with the student (if appropriate), the student’s parents, and school personnel involved with the student
  • Scatterplots or matrices tailored to the student that plot the relationship between instructional variables and student behavior over time and situations

By the end of the data collection process, the team should have sufficient quantitative data on the behavior and qualitative data to develop some guess or hypothesis about what function(s) the behavior serves for the student. It is these hypotheses that will lead to the intervention. There is an important point to be emphasized here: an FBA does not lead to a definite answer or “proof” of anything about the behavior. It leads to an “educated guess” which will then be tested or explored.


In light of the data collected and the team’s hypothesis about the function(s) the behavior serves, the team then develops a behavior intervention plan (BIP) that incorporates positive strategies, curricular or environmental modifications, and supplementary aids and supports. This means that if skills are deficient, the intervention might include skills training, whereas if skills are adequate but performance is inconsistent, the intervention might include positive strategies oriented to enhancing the student’s motivation to perform the desired behavior. If the FBA indicates that a learning disability is the antecedent for undesirable behavior, then curricular and instructional interventions may be planned, in combination with teaching the student alternative ways to communicate frustration or deal with the situation. Support from peers, school personnel, and the classroom teacher may also be incorporated, such as providing peer education, teaching peers to ignore the problem behavior, having the teacher privately cue the student when he’s about to get into trouble, etc.

Although the frequency and nature of monitoring of the plan is not clearly defined in the federal regulations, it makes good sense to monitor the plan to see if it’s being implemented as designed and if it’s working. If it’s not working after a reasonable amount of time, the team should reassess the situation.

The preceding was just a brief overview to familiarize parents with the logic of what is supposed to happen if their child engages in behavior that seriously interferes with their ability to learn or others’ ability to learn. A number of resources provide more detailed explanations of how to conduct an FBA. Links to some of these resources is provided on the companion web site for educators,

Theory aside, in actual practice, schools often fail to conduct an adequate initial assessment or seem to leap to an often-faulty hypothesis that the behavior is “attention-seeking” because they realize that whenever the student engages in the problem behavior, the teacher reacts. The teacher’s reaction may or may not be maintaining the behavior, but in any event, it does not follow logically that the primary function of the behavior was attention-seeking. By using multiple types of assessment and multiple sources of information, the team is more likely to develop a better hypothesis as to what function(s) the behavior serves.