How to Conduct a Functional Behaviour Assessment (FBA): A Parent-Friendly Guide to Understanding Behaviour

When I first learned about FBAs during my behaviour-analysis training, I assumed they were something only psychologists talked about in meetings. But over the years, I’ve noticed something interesting: parents are now the ones Googling it first — usually when nothing else seems to be changing and the “advice” so far has simply been: “Be firmer.”


If you’re reading this because you’re trying to understand why your child’s behaviour keeps happening, you’re in exactly the right place. My goal is to give you the clearest, calm explanation of what an FBA actually is, how it helps, and — importantly — what you can safely observe at home to support the process.

What Is a Functional Behaviour Assessment (FBA)?

In simple terms, an FBA is a structured way of understanding why a behaviour is happening.
Not just the behaviour you see — the reason underneath it.
A functional assessment looks at:

  • What happens before the behaviour (the trigger)
  • What the behaviour looks like (the observable action)
  • What happens after the behaviour (the consequence)
  • What your child gets or avoids as a result

Then a trained professional uses that information to work out the function of the behaviour — what the behaviour is doing for your child.

Here’s the key idea:

All behaviour has a purpose. Even when it feels random or “uncontrollable”, there is a reason behind it.

That’s why an FBA is not about judgement. It’s about discovery.

Why Behaviour Happens: The Four Functions (in Plain English)

Most behaviours fall into one of these four functions:

  1. To get something— attention, a preferred toy, help, closeness.
  2. To avoid something— a demanding task, a noisy environment, confusion, social pressure.
  3. Sensory reasons— for example: “It feels good”, “It blocks out other noises”, “It helps me calm down”.
  4. Communication difficulties— when your child can’t express the need they have, behaviour becomes the substitute.

These aren’t labels for your child—they’re stepping-stones toward understanding what the behaviour is seeking to do.

What a Good FBA Looks Like (and What to Watch Out For)

Because an FBA is part of a formal assessment, it should be done by someone trained in behaviour support (PBS/ABA) and/or working under frameworks like National Institute for Health and Care Excellence (NICE). It should involve a team: you (the parent), the school, and the behaviour specialist.

A good FBA includes:

  • Interviews with you and the environment (home, school)
  • Observations of behaviour in real places and times
  • A clear definition of the target behaviour (what exactly you see)
  • A functional hypothesis: “We believe this happens because…”
  • Link to a meaningful behaviour-support or intervention plan

A poor assessment often looks like:

  • “Yes, we did an FBA” tick box, but no clear description
  • Forms that ask your child: “Why do you misbehave? What should we do?” and assume behaviour is just a choice.
  • No parent input, no follow-up, no data beyond “We think it’s attention‐seeking”
  • No plan or the same “be firm” advice recycled

You deserve the first version.

Your Role as a Parent (and Why You’re Not Expected to Do the FBA Yourself)

Here’s something I see every day in parent forums: you feel responsible, you feel blamed, you wonder whether you should be doing it yourself. For example:

“I’m just after some advice … I keep hoping he grows out of it but it’s getting worse.” Family Lives Forum

Here’s the truth:

  • Professionals carry out formal FBAs because they require technical training.
  • You, as the parent, are the expert on your child’s real life — the person who has the “before” and “after” observations no one else buys into. The role is vital.
  • Your job is not to conduct the assessment alone but to contribute meaningfully.

When a school declines or delays an FBA, many parents feel powerless.

“Request a Functional Behaviour Assessment (FBA). If they refuse, ask for an IEE (Independent Educational Evaluation).” A Day In Our Shoes

You can absolutely ask. And you have a voice.

What You Can Do at Home: Safe & Meaningful Observations

These are observations that help you—and the professional—without crossing into “doing the assessment” medicine.

1. Notice “what happened just before”

Was there a transition, a noise, a question, a change in routine?

2. Describe the behaviour neutrally

E.g., “At 3:05 pm, when the teacher said ‘time to stop playing’, my child dropped the tray and walked away,” rather than “He threw the tray in tantrum”.

3. Notice “what happened immediately after”

Did someone speak to them? Did the demand stop? Did a toy get given?

4. What was the child trying to signal?

Even if they didn’t use words—what need might they have had?

5. Patterns matter

Instead of one incident alone, note if the same triggers appear across days.

These help reduce delays, misunderstandings, and support the professional to act more quickly.

What You Should Not Do

Because we must respect both ethics and safety:

  • Don’t try to test hypotheses (e.g., “I will remove demands for 10 mins and see what happens”) unless directed by a trained professional.
  • Don’t assume behaviour = “choosing to misbehave”. That leads to blaming and delays.
    • Example of assumptions: “The form assumes all behaviors are intentional.” endseclusion.org
  • Don’t withhold support, comfort, or warmth as a “test”.
  • Don’t design a full intervention plan yourself unless you’re trained.

How an FBA Helps Your Child

When done well, an FBA leads to:

  • Clearer understanding across home and school
  • Less confusion and fewer “why did that happen?” moments
  • A behaviour plan that actually fits your child’s needs
  • Better days — safer, calmer, more learning time
  • A stronger partnership between you and the professionals

Reassurance and Next Steps

If you’re reading this because things feel hard right now, let me say:
You’re not to blame.
Your child is not “just being naughty”.
You’ve been doing your best.
And you’re doing the right thing by seeking clarity.

Next Step: Use what you’ve started reading here, pick up your phone or email and ask:

“Can we look at the function of this behaviour? Can we gather observations together and ask for a proper FBA?”
You don’t need to wait. You don’t need to feel you’re “too late”.

You’re contributing — that’s huge.
You matter.

References

Hanley, G. P. (2012). Functional assessment of problem behavior: Dispelling myths, overcoming implementation obstacles, and developing new lore. Behavior Analysis in Practice, 5(1), 54–72.

O’Neill, R. E., Albin, R. W., Storey, K., & Sprague, J. R. (2015). Functional assessment and program development for problem behavior (3rd ed.). Cengage Learning.

National Institute for Health and Care Excellence. (2015). Challenging behaviour and learning disabilities: Prevention and interventions for people with learning disabilities whose behaviour challenges (NG11).

Gore, N. J., McGill, P., Toogood, S., Allen, D., Hughes, J. C., Baker, P., & Denne, L. D. (2013). Definition and scope for positive behavioural support. International Journal of Positive Behavioural Support, 3(2), 14–23.

Dunlap, G., & Fox, L. (2009). Parent-professional partnerships in early intervention. Infants & Young Children, 22(1), 3–17