Is It Really a Tantrum? Operational Definitions in ABA

In Applied Behavior Analysis (ABA), operational definitions are key to any successful program. A reliable and precise definition results in accurate data collection, which is the driving force behind the development of effective and ethical interventions. 

In this article, we’ll discuss what operational definitions are, why they are important, and how to write concise, clear definitions. Whether you’re a teacher, RBT, or BCBA, mastering this foundational skill will enhance your ability to observe, measure, and change behavior effectively.

What Is an Operational Definition?

In the context of ABA therapy, an operational definition describes a behavior in clear, objective, and measurable terms. To be a truly operational definition, any untrained observer should be able to read the description of the behavior and collect accurate data without ambiguity. 

As mentioned, operational definitions need to be clear, objective, and measurable. Specifically: 

• Clear – easily understood without needing additional explanation.
  
  
• Objective – based on observable behaviors, not interpretations or assumptions.
  
  
• Measurable – allowing for data collection methods like frequency, duration, intensity, or latency with clear beginnings and endings. 

Operational definitions are important as they are helpful in removing any ambiguities and personal interpretations. For example, let’s compare two definitions of “disruptive behavior”.

Vague: “He was being disruptive.”

Operational: “Disruption, defined as talking loudly without raising hand, leaving seat without permission, or making non-instructional noises for longer than 5 seconds. Non-examples include responding to the teacher when asked a question.”

The operational definition will lead to more accurate and precise data collection, while the vague definition will likely be interpreted in multiple different ways and yield incorrect and unhelpful data. 

Why Are Operational Definitions Critical in ABA?

Operational definitions are the backbone of effective behavior intervention. With any intervention, consistency across environments and people is key for children to learn in a safe and predictable environment. Operational definitions increase the chances that there is consistency across therapists, teachers, and caregivers in how procedures are carried out and when. For example, a manding protocol should specify when the child can have access to the desired item.

Having a definition like “Max will mand for an item using the three-word phrase ‘I want ____”. This ensures Max is clear on his expectations as he will receive consistent responses across the adults in his environment. A definition such as “Max will mand for an item” could lead to some caregivers reinforcing pointing, others reinforcing one-word utterances, and others demanding a complete sentence. This can create frustration and ultimately hinder the child’s learning, as he is unsure of what the correct and expected response is. 

The most effective way of ensuring a definition is operational is by focusing only on behaviors that are observable and measurable. For example, “feels happy” is not observable or measurable, as “happy” can look different to many different people. However, “smiling” is both observable and measurable, as you can see the facial expression, and you could measure the frequency or duration of smiling. This helps increase the validity and reliability of the data.

This improved accuracy helps ensure the data is valid and meaningful, which helps the BCBA with analyzing trends and understanding the behavior fully. This results in more effective decision-making, which should result in better intervention outcomes. The reason for this is that accurate data gives the BCBA a clearer and truer picture of what is occurring, so they are able to develop stronger interventions and subsequent program updates. 

Operational definitions are also important in reducing the chances of subjectivity and bias in treatment. This is essential to gather valid data, as prior ideas or hunches about the cause of behavior, etc, will not impact what is actually occurring. Despite a team being made up of different groups of people, the data should remain consistent. 

Key Components of a Good Operational Definition

A strong operational definition is clear, objective, and measurable. When we say clear, we mean the definition avoids using jargon or complicated language and should be specific enough for anyone to understand. The language should be straightforward, precise, and necessary.

For a definition to be objective, only what can be directly observed should be described. Operational definitions should be free of assumptions about how a person is feeling or the reasoning behind behaviors. The focus should solely be on what the observer can see directly. 

Definitions also need to be measurable, which specifies how to track the behavior. Behaviors need to have a clear beginning and ending, and should define what sort of data is being collected. For example, count, duration, intensity, etc. 

Contextualized definitions may be used as needed, which include information about the context or setting in which the behavior occurs. When using these types of definitions, examples and non-examples can help provide extra clarity.  Here is a definition of “work refusal” that incorporates context and examples as well as non-examples of the behavior into the definition:

• When presented with a demand, the student refuses to work verbally (saying “no”, “I’m not doing it”, “I don’t want to”, etc), and/or physically (pushing work away, looking away from work, walking away, etc). Non-examples include verbal refusal while working, requesting help, or requesting to leave the area.

Common Mistakes to Avoid

When writing operational definitions, there are a few mistakes to avoid. Firstly, using vague or subjective language such as “being disruptive” or “acting out”. Depending on who the observer is, this can be interpreted in different ways and will result in inaccurate and unhelpful data. Instead, be specific and observable. Instead, focus on what “being disruptive” or “acting out” looks like for that particular child. 

Second, avoid defining behaviors based on internal states. Commenting on internal states makes assumptions about how the child is feeling and is thus subjective. Furthermore, focusing on feelings often leads to circular reasoning, which offers no useful indications as to the function of behaviour. For example, “Jimmy is kicking because he is sad. I know Jimmy is sad because he is kicking”. As mentioned, focus on objective and observable language. “Feeling sad” will look different from child to child and is not observable. Instead, focus on what you can observe. For example, crying with tears, curling lip, screaming, etc. 

When writing an operational definition, it’s essential to strike the correct balance between being broad and narrow. Definitions that are too broad may include irrelevant behaviors, while definitions that are too narrow may exclude essential aspects of the target behavior. This becomes problematic because overly broad definitions can lead to the recording of unrelated behaviors, inflating data, and potentially skewing analysis. On the other hand, definitions that are too narrow may cause essential instances of the behavior to be overlooked, resulting in incomplete or inaccurate data collection.

Lastly, it is important to be mindful and aware that a child’s behaviors will evolve, and with it, the definitions should also be updated. For example, a tantrum behavior definition may have initially just included “screaming with or without tears and property destruction”. Over time, the child may have ceased engaging in property destruction but instead engages in aggression. If the operational definition does not account for this change, the data will be inaccurate, showing fewer tantrums than are occurring. 

How to Write an Effective Operational Definition

1. Identify the behavior of concern

Start by selecting the target behavior for the intervention. This will be a behavior targeted for reduction, such as aggression or elopement, or a behavior to teach or increase, such as initiating peer interactions or following directions. Focus on one discrete behavior at a time rather than mixing multiple behaviors into one definition.

2. Break it down into observable, measurable terms

Focus on what the behavior looks or sounds like using objective language. Avoid words that rely on interpretation, such as  “disrespectful” or “anxious,” and instead focus on what can be seen or heard. Using terms such as “angry” or “rude” is also difficult to measure accurately. Choose behaviors with clear beginnings and endings and specify these in the definition.   

For example:

• Instead of: “The student is defiant.”
• Use: “Defiance is defined as saying ‘no’ or refusing to follow a directive within 10 seconds of being given an instruction.”
• Include examples and non-examples

3. Use examples and non-examples

A valuable component of operational definitions is the use of examples and non-examples of the target behavior. This helps add extra clarity, helps prevent confusion, and supports interobserver agreement, especially when behaviors can be easily mistaken for others. Here is a definition of elopement, which includes a non-example of the behavior:

•  “Elopement includes leaving the assigned area (e.g., classroom, therapy room, or designated work area) by more than five feet without permission. Non-examples include walking to the classroom door to throw away trash after receiving permission from staff.”

4. Test the definition

A good question to check whether the definition is observable and measurable is: “Would two untrained observers be able to recognise this behavior in the exact same way based on the definition alone?” If the answer is no, the definition needs to be refined. Asking other staff members to review your definition can help indicate whether you are on the right track in terms of completeness and objectivity.. 

A practical formula to guide your writing is: Behavior = Action + Context + Criteria (if applicable). That is: 

• Action: What the person does (e.g., hits, screams, throws an object)
  
  
• Context: When or where the behavior occurs (e.g., during instruction, after a demand)
  
  
• Criteria: Optional parameters like duration, intensity, or frequency (e.g., for longer than 10 seconds, more than 3 times per minute)

For example: “Task refusal is defined as saying ‘no,’ closing eyes, or putting head down on desk for longer than 10 seconds after being presented with an academic demand.”

Examples of Strong vs. Weak Operational Definitions

Understanding the difference between strong and weak operational definitions is crucial for writing clear, measurable behavior descriptions. Let’s look at a few common behaviors and how they can be defined more effectively.

Tantrum behaviors:

• Weak definition: “Tantrums when asked to do something.”
  
  
• Strong definition: “Tantrum defined as two or more of the following: crying, screaming at a volume louder than speaking voice, dropping to the floor, and/or stomping feet for longer than 10 seconds after a demand has been placed. Non-examples include crying or screaming after falling, or otherwise injuring themselves.”

Aggression:

• Weak definition: “Hits mom when she says no.”
  
  
• Strong definition: “ Aggression is defined as any instance of hitting with an open or closed hand, kicking, biting, or throwing objects at another person within a distance of five feet after denied access.”

Task refusal:

• Weak definition: “refusing to do work”
  
  
• Strong definition: “Task refusal is defined as saying ‘no,’ putting head down, closing eyes, or walking away from a work area within 10 seconds of being given a task demand.”

Elopement:

• Weak definition: “running away from adults”
  
  
• Strong definition: “Elopement is defined as leaving the assigned area (e.g., classroom or therapy space) by more than five feet without permission and remaining outside the area for longer than three seconds.”

Operational Definitions in Practice

When conducting Functional Behavior Assessments (FBAs) and Functional Analyses (FAs), operational definitions are essential to obtain an accurate picture of the challenging behaviors. Clear and objective definitions eliminate guesswork and allow BCBAs to reliably determine the function of that specific behavior (e.g., escape, attention, sensory). If BCBAs misidentify the function of a behavior, they will create ineffective interventions that will waste time and may make the behavior worse.

Operational definitions are used in behavior intervention plans (BIPs) to define the target behaviors for decrease (e.g., aggression, elopement, tantrums) and the replacement or desired behaviors for increase (e.g., requesting help, using coping strategies). These definitions provide the basis for measuring progress and determining whether an intervention is working, as well as clearly stating what the child should be doing instead.

Operational definitions are equally crucial in skill acquisition programs. When teaching a new behavior, there needs to be a clear definition of what is a correct response, when the skill is considered mastered, and how the progress will be measured. For example, when teaching a child to greet others, the behavior must be defined clearly: “Greeting is defined as making eye contact and saying ‘hi’ or waving within 3 seconds of another person entering the room.” This level of specificity allows for accurate teaching, consistent prompting, and clear mastery criteria. 

Interobserver agreement (IOA) measures how consistently two or more people observe and record the same behavior. This is a useful tool to measure the reliability of the data and give an indication of whether the definition is operational enough. IOA is important to ensure the child is receiving consistent interventions across staff members and for the supervisor to be able to accurately monitor progress. For instance, if one observer includes “fidgeting” as part of “off-task behavior” while another does not, your data becomes inconsistent, and the child will receive different responses from each team member. 

Frequently Asked Questions About Operational Definitions

How detailed should an operational definition be?

Detailed enough that two people observing the same behavior would record it with high levels of IOA, but not so detailed that it becomes confusing. 

How often should operational definitions be updated?

As often as needed. RBTs should report to their BCBAs if they feel their client’s behavior has evolved. BCBAs should then conduct their own observation and make adjustments as needed.

What if different therapists interpret the behavior differently, even with a definition?

Revisit the definition and include more specific examples/non-examples, or adjust the criteria to reduce ambiguity. Conduct a data collection training session using videos or in real time and provide feedback. 

Can a behavior have multiple operational definitions depending on context?

Yes. For example, “task refusal” might look different during group work vs. individual instruction.

My Perspective as a BCBA

As a BCBA, I have always stated that consistency is one of the most important components of an ABA team. A child learns best when they trust and feel safe with their team, as they have established a clear and predictable relationship. Operational definitions are key to creating this consistency. 

For example, I have used token economy systems to help increase work tolerance with some students. Staff were trained on exactly which behaviors would result in a token and which would not. Having this clear expectation helped students become more motivated to work towards their reward. Furthermore, I was able to train the speech and occupational therapists, so the token board was successfully implemented across a multidisciplinary team. 

Conclusion

Operational definitions are a cornerstone of ethical and effective ABA therapy. They ensure that we speak the same language, observe the same actions, and make data-driven decisions that genuinely support clients. Whether you’re new to ABA or a seasoned professional, keep practicing, refining, and applying this skill. It’s one of the most powerful tools in your behavior-analytic toolbox.

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