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How To Do A Functional Behaviour Assessment

When we get asked for a quick and easy fix for a behavioural problem (eg: “What do I do when…”) our answer is usually, “It depends”. The solution to behaviour management lies not in the topography of the behaviour, but in the function that the behaviour serves. There can be two children who both engage in biting and it can look exactly the same. But when taking a closer look, it seems that one is biting for attention while the other is biting for escape. It is our job to be able to tell the difference and then choose an appropriate intervention. While you can take a guess, we encourage you to use a Functional Behaviour Assessment (FBA) – it is the gold standard in effective, function-based intervention.

What is a Functional Behaviour Assessment?

The premise is that no behaviour happens in a vacuum. All behaviours that we engage in serve a purpose for us and that purpose is what keeps the behaviour going. When I’m busy on the phone and my son wants my attention, he may resort to hitting his sister because then I’ll have to get off the phone and give him some attention!  As long as it works for him and he gets my attention, he’ll keep doing it!

The solution to problem behaviour lies in figuring which one of the four functions the behaviour is achieving: Sensory, Attention, Tangible, or Escape. Once we do that, we can apply a function-based intervention 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 behavioural intervention.

Steps to a Functional Behaviour Assessment:

1. Define the Behaviour

What is the behaviour in question? Is it worth targeting (for more on behaviours worth targeting, see When is a Behaviour Worth Targeting? There are a few criteria that we look for to determine this:

-Is the behaviour is getting in the way of learning?

-Is it compromising safety to themselves or others?

-Does the behaviour socially isolates the individual or decrease independence?

If the answer to any to these is “yes”, then it is likely worth reducing. Next, define the behaviour in terms that are observable and measureable. This means that instead of calling it “head-banging”, you might define it as “Any attempt to make contact between the forehead and an object, floor or wall.”

2. Collect Baseline Data

You want to collect as much information as possible to make your hypothesis as accurate as possible. Some ideas for data collection are:

-ABC data – these are data sheets that a teacher or caregiver can fill out that give us information about antecedents (what happened right before) and consequences (what happened right after). Make sure that they are collecting this ABC data (ONLY) on the behaviour previously defined, or you’ll be reading a laundry list of issues!

-Direct observation – ideally, you would be able to see that behaviour in person and be able to assess the antecedent and consequence. However, it may be likely that during the time of your visit, the behaviour doesn’t occur. Videotape can also be used for this purpose.

-Questionnaires and interviews – there are short answer questionnaires like the MAS (Motivation Assessment Scale) and the FAST (Functional Analysis Screening Tool). We also enjoy using the more recent Open Ended Functional Assessment (Hanley).

Depending on the situation and the environment that the behaviour is occurring, you might choose one or all three! Collecting some baseline data is important in determining the function but it’s also important in telling us if any intervention we try is actually effective in reducing the behaviour – it gives us what to compare it to.

3. Develop a Hypothesis

After reviewing the data, you should be able to come up some sort of hypothesis about the function:

-Is the behaviour always occurring when the child is given a demand?

-Are there any other setting events (eg: didn’t sleep well at night)?

-What kinds of consequences is the child receiving?

Remember: it can be more than one function, like escape TO tangible.

If the function is clear from steps 1-3, proceed to step 5.

 4Test the Hypothesis (this is the analysis part)

If after steps 1-3 the function is not clear, you might want to consider progressing to a functional analysis. A functional analysis is when the behaviour in question is elicited and reinforced in order to determine the function. While very effective, there are risks involved with a functional analysis so the benefit must outweigh the cost. For example, if a FA will elicit dangerous behaviour, it might be better to omit.

Disclaimer: A functional analysis should only be done by an experienced BCBA. If you are unsure if that is you, find some training or mentorship.

5. Develop Interventions Based on Hypothesis

Now is the time for the plan. With a function-based intervention, we can tailor the behaviour plan to help the child achieve the same function in a more appropriate way. Since behaviour is communication, he first step is always teaching functional communication training. For example, If the child is engaging in behaviour for escape, we can teach “I don’t want to” or “I need help”. Make the chosen FCT as easy as possible for the child to use; it can even be exchanging a picture or a sign.

Always include antecedent strategies. Most of the time, if you’re already on the consequence side of the behaviour, you’re too late. Teaching the child to replace the behaviour involves some proactive strategies. Some ideas include: using a visual schedule, non-contingent breaks, and a reinforcement system. Define the positive opposite of the behaviour and reinforce it so that it increases!

Even with FCT and antecedent strategies, there will likely be times that the behaviour still occurs (i.e., extinction burst). At this point, we’re doing damage control. It’s important to get everyone on the same page and NOT ALLOW ACCESS TO THE FUNCTION OF THE BEHAVIOUR. If the function of the behaviour is escape, then do not allow escape; if the function is attention, then do not provide attention, etc. The more a child sees that the negative behaviour doesn’t get what he wants, the less it will happen.

Want more on writing a behaviour plan? We have an entire video training on the topic including templates of behaviour plans that you can download, all in The Bx Resource! Check it out:

3 thoughts on “How To Do A Functional Behaviour Assessment”

  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

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