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Part 1:

Learning your


The first step in Function-Based Problem Solving is to get a good “picture” of the behavior.


In other words, you’ll need to get a good understanding of all that influences the specific behavior(s) of concern.

To do this, you'll first need to know your ABCs…not the alphabet, but your Behavior ABCs, sometimes referred to as the "three-term contingency:" Antecedent, Behavior, Consequence

What are antecedents and consequences?

Antecedents are what immediately precedes, or triggers behavior to occur. A good way to remember what they are is to think of them as “cues” that “signal” when a behavior will be reinforced. Common antecedents include task demands (especially difficult ones), a specific classroom, transitions, being ignored by a teacher, and being given a request. Antecedents essentially set the stage for problem behavior, making it more likely that it will occur. However, they also play an important role in behavior prevention, as we will discuss later.

“A substitute teacher can sometimes be an antecedent for problem behavior. In this situation, the presence of someone other than the students' teacher signals that talking loudly, pretending to have homework already turned in, and off task behavior in general will be reinforced, allowing the students to escape from their school work.”

(University of Kansas)

A Little Note About Setting Events

Many resources will include Setting Events (SEs) as a separate component of the 3-term contingency. SEs are “global life influences,” (i.e., hunger, fatigue, illness), that impact our ability to cope with certain environmental variables (NJ PBSIS, 2015). SEs do not immediately precede behavior, but instead, operate in conjunction with antecedents. SEs make it more likely that an antecedent will trigger problem behavior (e.g., if I am already sleepy and encounter one of my least favorite classes, it is more likely that I will disengage). For simplicity, we refer to SEs within the general antecedent category.

Consequences on the other hand, are what we all tend to focus on when responding to behavior. They are what happens directly after the behavior occurs, or the outcome. This would include things such as what the teacher does when the behavior occurs, what other students may do, and also, of course if the student is sent somewhere after exhibiting the behavior.

Why ABCs?

As educators, we often inadvertently reinforce the very behaviors that we identify as concerns. This happens because we are not fully aware of 1) the function of the behavior and 2) the reinforcing power of our actions. Through the use of the ABC process, we can have more insight into why a behavior is occurring, which allows us to more appropriately address it.  

Step 1: Define the Behavior

The easiest way to begin the ABC process is to start with the "B," and identify the behavior of concern.  Before you can determine what behavior you are defining, you’ll need to clearly assess the problem that you’re having:


Guiding Questions:

  • What is the problem behavior?

  • If there are multiple behaviors, what is the most pressing, harmful, difficult, etc. behavior?

  • What does this behavior look like?

  • What exactly did you see, the last time this behavior occurred?

  • How can we define the behavior in quantifiable terms? In other words, how can we measure it?

A Little Note About Baseline Data

It is good practice to collect baseline data, or data prior to the start of intervention. Collecting baseline data about the ABC process can provide more specific information, leading to the development of a more appropriate intervention. Additionally, the collection of baseline data allows for you and your team to compare the severity of behavior before, during, and at the conclusion of the intervention.

To collect baseline ABC data, you will need to observe the behavior occurring at least 3 times, and record your information using this form. Detailed instructions can be found here.

Behavior Description

Your description of behavior should be “operational,” or defined in a way that is observable, measurable, and repeatable, and refrain from referring to any personal feelings or opinions you may have about the student and/or what they are doing (e.g., Gregory is being manipulative).

What is so important about this step? Well, if we do not know what behavior we are specifically trying to target, how will we know when progress is (or is not) made? Often, there seem to be SO many behavior concerns, that individual behaviors get lumped into one "overarching" behavior. It is helpful, to identify these specific behaviors so that a more accurate understanding of student progress is achieved.


Let’s use my friend Timmy (and his behavior) for example:

Timmy’s Problem Behavior: Off-Task

What’s wrong with this? I’m sure that was an easy one: it doesn't tell us anything! While I may know what being off-task means in a general sense, two different people may have vastly different explanations for what this looks like. You never want to leave behavior descriptions up to interpretation. It causes confusion which can lead to inaccurate assumptions, thus leaving more room for error when developing your plan.

So what should your behavior description look like?


It should:

  1. Follow the basic assumptions of behavior (link)(e.g., be observable and measurable)

  2. Include a label for the behavior

  3. Should be stated in positive terms

  4. Include examples of what it "looks like" for the individual student

  5. Include "non-examples," or what the behavior is NOT


Let’s use Timmy’s behavior again:

Problem Behavior: Timmy does not do his work


While this is a tad (and that’s stretching) better, it still:

  • Is not stated positively

  • Is vague (does not include examples/non-examples of the behavior)

As you would guess, this alone would be insufficient, leaving me to ask the following questions:

What does this mean? Does he not do any of his work? When does he do his work? Is this the case in all of his classes?


Instead, be specific:

Timmy is off-task (label) during independent work time. He engages in the following behaviors (examples): laying his head down on the desk, talking to classmates, yelling the teacher’s name, working on unassigned tasks, reading a personal book

Non-examples (non-examples) include: working on his assigned tasks when instructed to do so, only discussing the assigned work with his peers, raising his hand


What we find here is that not only is Timmy off-task, but is also pretty disruptive! Again, had we stuck with the previous examples, we may not have known this specific information. It would make sense at this point to add disruptive behavior to his list of behaviors and define off task and disruptive as two separate behaviors (because you can be off-task and not be disruptive).


Here are some examples of common student behaviors and how they might be more explicitly defined. Find others on our resource page!

Quiz YourselF! 

Think you have it all down? Use this worksheet from the IRIS Center to practice developing operational behavior definitions.

Step 2: Identify Antecedents to the Behavior

Now that you have objectively defined your behavior, the next step is to identify the "A," or its antecedents.


Remember that antecedents are what happens before the behavior occurs. To identify antecedents, you can use these guiding questions:

  • When (e.g., time of day, subjects) does the problem behavior usually occur?

  • Where does the problem behavior usually occur?

  • Where and when does the behavior not occur? In what circumstances is it least likely to occur?

  • Are certain staff or students present when the behavior is more likely to occur?

  • What activities or events immediately precede the problem behavior?

  • What things do teachers, staff or students say or do, immediately before the problem behavior?

  • What is the student doing right before the behavior occurs?


Let’s use my friend Timmy, again. This time we will just focus on his off-task behavior (not the disruptive):



Right before Timmy engages in off-task behavior:

Timmy is asked to complete an assignment

It is independent work time (i.e., he is supposed to be completing the work on his own)

He is in his math or reading period


You have completed 2 out of 3! Yay, you! Let's move on to "C," or the consequences that occur as a result of the behavior.


Step 3: Identify Consequences of the Behavior

When I refer to consequences, remember I am talking about what happens right after the behavior. It is important to consider both immediate and delayed (i.e., occuring at a later period, but in response to the behavior) consequences when examining behavior (NJ PBSIS, 2015), but for simplicity, we will just look at what immediately follows student behavior, as this is a lot harder, sometimes, to ascertain.


You guessed it! Timmy is back!



The teacher asks Timmy to get back to work

The teacher offers two additional reminders to get on-task

Timmy is sent to the principal’s office


This chunk of the three-term contingency is very important to identify because it helps us identify any patterns surrounding the behavior and ultimately, the purpose of exhibiting the behavior. After you identify these, it’s helpful to consider the following:

  • Why would a student want to …(insert whatever happens after the behavior).

  • Is the student able to get access to anything preferred after the behavior (such as staff, tangible items, certain peers)?

  • Does the student usually get to avoid anything non-preferred?

  • How long is a student away from academic instruction following these behaviors?

  • Do all staff/students respond to the behavior in the same way? If not, what differences exist across certain staff/students responses and how the student acts?

If we were to examine Timmy’s data, how would you answer these questions (hypothetically speaking)?

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Step 4: Develop a Function Hypothesis

Once you have your ABCs, the next step involves reviewing this contingency to develop a function hypothesis, or why you think the behavior is occurring. Answering the questions above, helps to determine this.


Based on our ABC information, we hypothesize that Timmy engages in off-task behavior to avoid math and reading work.


You can use the following template, summarizing your findings and inserting them into the appropriate section: 

When (A) occurs, the student exhibits (B), and (C) happens.


Example: When Timmy is asked to complete a math or reading assignment on his own, he lays his head down on the desk, talks to peers, and works on unrelated assignments. As a result, Timmy is sent out of class.


Add your hypothesis at the end, to summarize: 

It is hypothesized that the student does (B) to (insert function).


Example: When Timmy is asked to complete a math or reading assignment on his own, he lays his head down on the desk, talks to peers, and works on unrelated assignments. As a result, Timmy is sent out of class. It is hypothesized that Timmy engages in off-task behavior to avoid completing math and reading work.

Helpful Tips:

  • Write your ABCs so that someone who does not know the student will be able to immediately identify when the behavior is occurring

  • Be as descriptive as possible, with your behavior definition; the more details, the better!

  • Make sure that if you have identified multiple behaviors for a student, you complete this process for each "set" of behaviors

  • If there are other behaviors that occur under completely different contexts, you probably need to define separate antecedents and consequences for it

And that’s all folks (to Part 1, at least)!! In the next step, you’ll learn how to put this information to work and determine what strategies to put in place to address the behavior(s) of concern.


Continue to Part 2.

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