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How to Write a Functional Behavior Assessment

functional behavior assessment

What is an FBA?

How to write a Functional Behavior Assessment starts with knowing what it is! A Functional Behavior Assessment or FBA is a process that is used by school personnel as part of the IEP process or private clinicians to determine what’s evoking challenging behavior in a student or client. The FBA process is the gathering-information portion that often leads to the plan portion or Behavior Intervention Plan (BIP). For the purposes of us today, I will use the term FBA to mean both the FBA and BIP process because, while not always, the process usually includes the prep AND plan pieces (enough “p's” for ya?).

Who is qualified to write an FBA?

Technically, almost anyone CAN write an FBA with some training; there is no legal requirement. However, a really good FBA, meaning one that is most likely to make significant change for the student, takes training and experience to do well. Each school district will have their own methods, but usually a behavior support team, a psychologist, a BCBA (Board-Certified Behavior Analyst), or a special education teacher will be the driver of the plan. It’s a team process, though, so everyone should be involved in some capacity!

What I have seen most effective is saving the “heavy hitter” FBAs for the most experienced, typically a BCBA or someone with extensive experience developing behavior plans, and plans for students with less significant behaviors can then be done by the special education teacher or psychologist. But, do what works for your team!

What does an FBA consist of?

Most FBAs, once through the whole process, will include the following:

  • Background and history
  • Synopsis of data collected
  • Summary statement with clear, concise, and accurate definition of behavior including function
  • Proposed strategies
  • How data will be collected and analyzed
  • How the team will know when to modify or consider the plan “complete”
  • Signatures to confirm everyone has read and is in agreement with the implementation of the plan
fba balanced approach

Plans typically run 4-20 pages (or even longer!) depending on the complexity of the student, the behaviors, and the environment. It's important to be thorough enough to capture important aspects, but not so verbose or technical that people on the team are overwhelmed or unable to follow the plan! It's a balancing act.

How long does an FBA take to complete?

As long as it takes to get right.

But I know that’s not helpful. I have written some FBAs for students I know well and already have good data on in a few days. Most of the time, however, it takes a good 4-8 weeks to develop a full and complete FBA. There needs to be enough time to gather background information, to collect solid baseline data, to analyze it, to make a hypothesis, to consider certain strategies and make sure they’ll be effective, and then to put it all together, get people on the team together, present it, train, follow-up, you get the idea. It takes time.

When it’s done well, though, UH-mazing! You really are able to drill into a behavior, look at the environment, what will work/not work for that student, and make meaningful change for the student AND the team. It’s worth the effort! Not every challenging behavior needs this level of attention; some do, and it's worth the time you put into it.

What is the FBA process? How to write a Functional Behavior Assessment

I broke my process down into 8 steps. I hope they help you!

1. Gather information

The first thing I do is to gather as much general information as I can about the student and the behaviors of concern. Chat with parents, teachers, other staff, find out past history, consider how trauma may impact the behaviors, find out when the student does really well and when they struggle. Sometimes, depending on the student, I may do one observation of the student FIRST (if I already have consent) before gathering background information. It helps me visualize the student when I learn more from family and staff. 

fba interview

Also in this first step is to get parental consent for the FBA. No direct observation or data collection can be begin until consent is given and parents know what is going on. 

This is also when to look at the current IEP, review past behavior plans, review health records if available. 

2. Make direct observations

student observation for fba

Here is where I get to see for myself what others are reporting. I find when doing observations, it's important to 1) observe the student during a time they are reported to do well; 2) observe when it's reported they struggle; 3) and make sure they are different settings like one during a structured time and one during unstructured. I like to do at least 2-3 observations to really get a picture.

This is not a time for me to interact or try a strategy. I just sit back and watch! Take notes! What is happening in the environment? Is there a trigger I can identify? What does it appear the student is seeking? How do the people and environment respond? 

I'm mindful if the student knows me or if my presence seems to change their behavior. If so, I finagle it in such a way as to prevent that! I've been known to sit behind a divider and look between the cracks to not get observed by the student! You want to see the student in their typical environment, not changed because the student (or the teacher) knows I'm watching!

3. Collect measurable baseline data

Once I feel like I have a good feel for the behavior in question, now it's time to take (and have staff take) objective and measurable baseline data. Depending on the behavior in question, this can take many forms. 

I like to have staff start, even as early as step 1-2, taking simple A-B-C data. This means just having them jot down what's happening before a behavior, what the behavior looked like, and what happened after. While I don't use this as objective and measurable data, I get a good idea from this about what to design for data collection going forward.

fba collect data

With that information, I will design as simple a data collection system that staff can learn to take but will also capture clearly what's happening on an on-going basis. This could be interval recording, rate of behavior, duration, and so on, just depending on what the behavior is, how often it happens, how long it lasts, how intense it is, and what staff are available.

Also VITAL to make sure staff CAN take the data and take it to fidelity meaning that it's reliable. If I've trained this person to take the data, and they hand me a data sheet, I'm confident it captured what truly happened in that setting. 

I will generally take data like this for at least two weeks so that I can identify any trends. 

4. Hypothesis and Definition

fba hypothesis

Once I have enough data that I can see trends and have a good idea of what's going on, now it's time to make my hypothesis. I will create a true operational definition of the behavior meaning describe it in such a way that anyone that reads it can identify the behavior when it occurs in real time. I will also make my hypothesis on the FUNCTION of the behavior which is vital to know going forward. 

A word about the target behavior. I've learned over the years how important it is to teach teachers and staff that an FBA is a laser pointer, not a net. We want to focus on the behavior that is preventing the student the MOST from participating with their peers, not attempt to “fix everything.” 

When you clear a path in the forest, you move the biggest items first... the trees, the large rocks. Once the large items are out of the way, then you can move the smaller items. Eventually, the path is clear. When designing a behavior plan, focus on the biggest barriers first. Worry about the little things down the road.

As an example, I wouldn't define a behavior, “Student throws a tantrum when they are given a math sheet.” Instead, it might look like, “When presented with a worksheet with more than half a page of work to complete, Student is likely to engage in task-avoidant behaviors such as ripping the paper, throwing the pencil, crying, and/or falling to the floor for at least 5 minutes in order to avoid the work.” I will include baseline data here like, “This occurs an average of 4 out of 5 presentations of tasks over three days.” 

At this stage, also, I may adjust the data collection measure. But now, I know much better exactly WHAT I want to measure, and I often want to simplify and focus on it to make it easier for staff.

Find some data collection ideas here

5. Determine replacement behavior​

So now I have zoomed in to the behavior I want to target. I have a good idea of what needs the student is expressing with their behavior. I know about the environment and what might be contributing to the behavior. Now, let's think of something to TEACH! 

When thinking about what new behavior I want to teach the student, I'll keep this in mind: 1) it must be something the student can ALREADY do (or at least be taught to do easily), 2) it must be something that can be taught and used in their current ENVIRONMENT, and 3) it must meet the SAME NEED as the challenging behavior. 

fba replacement behavior

Let's say the challenging behavior is leaving circle time after 10 seconds, function determined is escape. Possible replacement behaviors: teach functional communication such as “I need a break.” That can be a break card or verbal. Must be something that the student CAN do, even if they aren't right this minute. But you know they can, and they have other communication modalities they are successful at. 

We're not talking about strategies to make them stay in circle time right now. We are just trying to REPLACE the current challenging behavior with something more functional. So, instead of getting up and leaving, now we are going to teach them to say, “break,” and THEN they can get up. 

So we are going to take data on the new behavior going forward. We want to see THIS behavior increase as we implement the other strategies (and we hope to see the eloping going down at the same time).

whats the function of behavior

6. Determine Strategies

fba strategies

Next we want to think about ALL the different pieces we can put in place to support an increase in the replacement behavior and a decrease in the challenging behavior.

These should include antecedent strategies (things we do beforehand), environmental changes (what we can do around the student to make things easier for them), teaching strategies (in addition to the replacement behavior, what other things can we teach to support the plan), and consequence strategies (what are we going to do if and when the behavior does occur). 

In the example of the student at circle time, maybe we can offer their favorite character chair to sit on or favorite fidget to hold, maybe we can have the most exciting things at circle time at the beginning to get them to stay longer, maybe we can have a favorite para sitting near them, maybe we use first-then to get them to stay just 2 seconds more each day, or a token board. When they leave without using “break,” maybe we escort them back to circle and immediately prompt them to say “break” and THEN “Oh, you want a break! Sounds great!” Maybe we have an alternative activity ready for them, not a highly preferred one, but something else to do when they request a break. You get the idea. 

extinction burst

7. Meet, approve, disseminate

Once I have a plan and the team feels confident we'll see behavior change from its implementation, it's time to reconvene the whole team, get everyone's stamp of approval (including the family!), and make sure everyone is on the same page going forward. 

This doesn't mean that everyone who comes in contact with the student needs to have the 14-page copy of the entire plan (although those that helped develop it should have it all), but  there can be a scaled down version for any staff or personnel who need to be involved, something quicker and easier to read, digest, and implement. 

fba meeting

I like to create a couple things for this. I create a one-page checklist that includes all the strategies we've come up with, a quick snapshot of the plan, that can be easily referenced and even used to make sure the pieces of the plan are followed during an incident. I also like to create a “Crisis Cycle” for students whose behaviors are significant or have a longer duration who go through a full crisis or trauma cycle. This is also a one-pager and includes their personal crisis mountain, what they look like when they're calm, when they're anxious, when they're exhibiting precursor behavior, what their risk behaviors look like, and their recovery stage. Next to each of those stages, I include simple strategies that staff can use for the student in that moment. 

I guess the last thing that can be easily handed out is the data sheet you would like the staff to use when tracking behavior over time! Just make sure the staff you have taking data have training so that what data you get back is reliable (as always!).

8. Analyze and Modify

collect data for fba

And lastly, remember than an FBA (especially the “plan” portion!) should be a living, breathing document. Data should be taken consistently, and the driver of the FBA should be looking at it, analyzing if the plan is working, and tweaking it as needed to make progress! This doesn't always need to be a big team meeting; little tweaks are like changing how you're tracking data or modifying a certain strategy to be more appropriate to a new setting or something like that. 

However, if you see that progress is or is not being made like you wanted to see, reconvene your team! Bring the brains together, and see if bigger changes need to happen to benefit the student. 

It isn't until you have met the mastery criterion you set for the plan that you really have that “all done” stamp, so keep watching, taking data, tweaking, meeting, and supporting! You'll get there! Consistency is key!

fba consistency is key

Some of my favorite finds for data collection!

This clipboard has a compartment to keep additional papers. Great if you keep losing stuff!

I love these whiteboard clipboards. I use them as an impromptu visual or token board for the student I’m working with. 

These small clipboards are great for portable data taking. I also use them to create student activities like spell-your-name-with-Scrabble-tiles!

The most durable and reliable clicker to count behaviors.

And these mini count clickers are amazing! Tiny and portable!

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Find hundreds of resources for special education, ABA and data collection, social skills, and early intervention!

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