How to complete an FBA

What is functional behaviour assessment?

Functional behaviour assessment (FBA) is a process for collecting information to help determine why certain behaviour occurs and to serve as a basis for the development of behaviour support plans. Research has shown that FBA is a useful process for developing effective interventions.

FBA aims to:

  1. define behaviour in specific, observable and measurable terms
  2. determine what aspects of the environment or situation contribute towards the behaviour
  3. identify the consequences which maintain the behaviour.

What is an A-B-C chart and can I use one in my classroom?

An A-B-C Chart is a direct observation tool that can be used to collect information about the events that are occurring within a student’s environment. “A” refers to the antecedent or the event or activity that immediately precedes a problem challenging behaviour. The “B” refers to observed behaviour, and “C” refers to the consequence or the event that immediately follows a response.

A-B-C data is a form of data collection which can assist with functional behaviour assessments. The data collected can help to create a picture of the possible function of the behaviour (escape, access, attention, automatic reinforcement). This is an important part of creating an effective intervention to increase appropriate skills and decreasing maladaptive behaviours.

Taking A-B-C data

  • Antecedent (A): Record events or interactions that happen DIRECTLY BEFORE the behaviour occurs.
  • Behaviours (B): Should include only OBSERVABLE Do not include guesses at internal states as emotions. Be as specific as possible.
  • Consequences (C): What occurs DIRECTLY AFTER the behaviour, including verbal interactions from staff/peers, physical interactions from staff/peers, and any type of prompting.

Considering antecedents and consequences

There are common antecedents and consequences that occur and that are particularly important to identify in A-B-C data collection. Here are some common examples of items you may include in your A-B-C data recording when relevant.

Antecedents: demand/request presented, difficult task presented, transition, being told “no” or “wait,” alone (no attention being given), or free play (child playing with toys with no demands).

Consequences: Request repeated, behaviour ignored, attention (specify what attention looks like, such as reassuring statements or stern tone of voice, etc.), a student told to take a break, or student is given a preferred item (item he wanted or another item he generally prefers?).

Tips for A-B-C data collection

  • You must have multiple A-B-C scenarios collected with clear and detailed information to be able to hypothesize the function of the behaviour.
  • You might also add setting events to an A-B-C data chart. Setting events are “the events that momentarily change the value of reinforcers and punishers in a student’s life. The occurrence of a setting event can explain why a request to complete a task results in challenging behaviour on one day but not on the next.”
    • Examples of settings events include the time of day, environmental arrangements such as what classroom the student is in, illness, hunger, lack of sleep.

Functional Behaviour Assessment eLearning

Introduction to Functional Based Assessment (FBA) eLearning provides the foundations for understanding behaviour and that all behaviour is functionally related to the environment. By understanding why and when behaviours occur educators can develop, implement and evaluate interventions that better meets the needs of the student.

Access the Introduction to Functional Behaviour Assessment (FBA) eLearning


If you would like to provide feedback on this resource, please complete the Feedback form.


  • Teaching and learning

Business Unit:

  • Inclusion and Wellbeing
Return to top of page Back to top