What is a functional behaviour assessment?
A functional behaviour assessment (FBA) is a process for finding out why a challenging behaviour happens. Staff define the behaviour, record when it occurs and what happens before and after, look for patterns, and form a hypothesis about its function, such as gaining attention, escaping a task, getting an item or sensory needs. The findings shape a behaviour support plan.
What this means in practice
Without understanding function, interventions often backfire. For example, sending a child out of class may reward behaviour that was meant to escape a difficult task.
Steps in an FBA
- Define the behaviour in observable terms.
- Collect ABC (antecedent-behaviour-consequence) data.
- Interview the child where possible, the family and staff.
- Identify patterns and likely function.
- Write a support plan and test it.
Who conducts it
In schools, FBAs are often led by special educators, behaviour specialists or psychologists, with teachers and shadow teachers collecting observations.
Common functions of behaviour
- Attention: the behaviour gets adult or peer attention.
- Escape or avoidance: it ends or delays a difficult task or situation.
- Tangible: it gets an object or activity the child wants.
- Sensory: it provides or reduces a sensation.
- Many behaviours serve more than one function, so look at patterns across situations.
- The function guides the replacement skill: a child seeking escape may need a break card, while a child seeking attention may need a way to ask for it.
Practical next steps
- Choose one behaviour to understand.
- Collect ABC data for two weeks.
- Look for patterns in time, task and setting.
- Plan and test changes.
What to keep in mind
Behaviour that risks serious harm needs immediate safety planning and specialist support.
Common follow-up questions
How long does an FBA take?
Often two to four weeks of observation, depending on how often the behaviour occurs.
Can parents contribute to an FBA?
Yes. Home observations help identify patterns.
Sources
- IRIS Center, Vanderbilt University: special education modules
- Center on PBIS: Positive behavioral interventions and supports
Sources inform the explanation; examples are educational illustrations, not individual clinical advice. How these answers are prepared.