Examples of Operational Definitions: 3 Key Components

Applied Behavior Analysis (ABA) requires careful collection and assessment of data to inform treatment decisions. Operational definitions allow for consistency in data as these definitions offer little confusion as to whether a behavior has occurred. Learning to write these types of definitions often feels daunting to professionals just entering the field.

Although they require some practice to write effectively, operational definitions are a key component in writing your behavior intervention plan (BIP) or when collecting data about specific behaviors. Operational definitions allow you to convey either what the behavior looks like (topography) or what function the behavior serves while providing sufficient detail to be clear. Take the time to practice and refine how you write your operational definitions!

Before you go on, learn the details about how to write operational definitions in our FREE course: Writing Operational Definitions. Each definition follows a set pattern and the course will provide this structure for you. In the course, there’s an opportunity to practice operationally defining behaviors (see the image below). If you prefer an article, read: Clearly Define the Behavior.

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You can also download a PDF with these examples.

Operational Definition of Aggression

Aggression is commonly targeted for behavior reduction but can be difficult to define objectively as it’s really the effect on another person that we are concerned with and it often encompasses many different behaviors.  Many children engage in multiple different types of aggressive behaviors including hitting, kicking, biting, and more.  If your definition includes more than one of these behaviors, make sure each is also clearly defined.

When defining aggression, many try to make as broad a definition as possible to include attempts at aggression and mild aggressive behaviors.  Instead, consider targeting the behaviors that present the most imminent risk of harm.  As these behaviors reduce, you can then target “inappropriate physical contact” to address low risk behaviors. 

Defining aggression may take more training of your interventionist than other definitions.  Many people feel as though they already know what aggression is and use their own definition rather than relying on yours.  Be clear with your interventionist about the threshold for aggression.  If they want to include attempts or light hitting, assure them that you will target those behaviors once you have a sense of the scope of the truly dangerous behavior.

Here’s an example:

Aggression: Any instance of Richard making physical contact with another person using his body or an object with enough force to cause an audible sound and/or leave a visible mark on the skin.

Examples Include:

  • Biting- teeth making contact with any part of the skin, constricting and leaving a mark
  • Hitting- using a hand or arm with a closed or open fist to hit (making forceful physical contact) with another person
  • Kicking – using the foot/feet or leg/legs to make contact with another person
  • Throwing objects – any instance of him throwing items that are not designed to be thrown with enough force that the object makes physical contact with another person’s body making a sound on contact (not upon the object coming in contact with the floor) and/or leaving a mark on the person’s skin

Non-Examples Include:

  • Giving a high five
  • Hugging
  • Common social physical interactions
  • Saliva leaving his mouth as a result of talking or yelling

Operational Definitions for Self-injurious Behavior

Self-injurious behavior, also referred to as SIB, is similar to aggression in a lot of ways.  The primary difference is the target.  The child inflicts injury on himself or herself rather than another person.  As with aggression, SIB may encompass many different topographies of behavior which may make it difficult to define. 

When writing your definition, determine how specific or broad you want to be depending on staff skill, your plans for intervention or other factors.  If you include multiple topographies of the behavior, consider including separate definitions for the topographies as in the aggression example above. 

The following definition provides examples of each topography to ensure clarity:

Self-Injurious Behavior:  Any instance in which Liam engages in any of the following: hitting self, pinching self, banging head on surface, slapping or biting self with sufficient force to make a sound and/or leave a mark.

Examples Include:

  • Banging the front or back of his head on a hard surface.
  • Hitting his head with his hands.
  • Pinching his legs, arms or cheeks between his thumb and forefinger.
  • Biting his hand, arm or leg by placing teeth on skin and compressing with sufficient force to leave a mark.

Non-Examples Include:

  • Bumping his head on the ground when flopping to the floor.
  • Banging his open hand on a table or hard surface.

Alternatively, you might choose to define just one topography of SIB if the child isn’t prone to multiple topographies or if you plan to treat different topographies separately.

Here’s an example:

Hand Biting:  Any instance in which the teeth come into contact with any part of the hand with sufficient force to leave a mark.

Examples Include:

  • Biting the hand between the thumb and forefinger with sufficient force to leave a red mark.
  • Biting the hand below the thumb knuckle with sufficient force to leave teeth marks.

Non-Examples Include:

  • Putting a finger in the mouth without leaving a mark.
  • Putting the side of the hand in the mouth without leaving a mark.
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Operational Definitions for Non-compliance

Non-compliance is another common behavior that is tricky to define.  In ABA it actually isn’t considered a behavior because it doesn’t pass the Dead Man test.  The Dead Man test states that if a dead man can do it, it’s not a behavior.  Can a dead man fail to comply with a direction?  Sure.  Non-compliance is not a behavior.

That being said, in practice, you may be in situations where it’s reasonable to target this as a behavior for reduction.  You may feel better about defining this as a behavior if you call it “Refusal” even if the child doesn’t actively protest when given a demand.

Here’s an example of a definition of this non-behavior:

Non-Compliance: Any instance in which Alex physically and/or verbally refuses to follow an instruction or complete a task.

Examples Include:

  • Alex swiping materials off the table when presented with a task to complete.
  • Alex refusing to complete a transition when directed to (may or may not flop on the floor).
  • Alex not moving his body to initiate the task/follow the instruction within 30 seconds of the demand.

Non-Examples Include:

  • Alex engaging in a response that matches the delivered instruction.

Onset: 30 seconds of occurrence

Offset: Initiation of compliance with directive

*Note that onset and offset have been included in this definition as it’s a “behavior” that doesn’t have a clear start and stop so would likely be recorded using duration recording.

An alternative to trying to define a behavior that’s not actually a behavior is to target the opposite of that behavior for increase.  Here’s what I mean: target compliance with adult demands for increase.

Here’s what that might look like:

Compliance: Any instance in which Alex follows an instruction or completes a task as directed by an adult within 30 seconds.

Examples Include:

  • Alex completing a transition within 30 seconds of an adult requesting he do so.
  • Alex engaging in a behavior specified by an adult.

Non-Examples Include:

  • Alex taking longer than 30 seconds to initiate a task after being given a direction from an adult.
  • Alex starting a transition when directed to do so but flopping after taking only 5 steps.

Operational Definition of Flopping

Flopping looks different for many children and the definition should reflect what is common for your client.  In addition, you should consider whether you want to include aspects that are less common for your client.  For example, if your client typically falls flat on the floor on his back, do you exclude all other topographies?  How should staff respond if he falls to his knees or stomach?

Make sure to purposefully include or exclude each topography based on your desire to either restrict or expand the definition.  This should reflect your plan in how you want your interventionists to collect data and implement a Behavior Intervention Plan.

Take a look at this example:

Flopping: Any instance in which the Julian’s body goes limp resulting in his body in a kneeling or lying flat on the floor position.

Examples Include:

  • Falling to his knees while walking in the hallway.
  • Moving from standing to lying flat on the floor when given a directive by an adult.

Non-Examples Include:

  • Lying on the floor in the motor room as part of a game he is playing.
  • Kneeling on his mat at circle time.

Operational Definition of Eloping

Eloping is a behavior you might define as either a discrete event or as a duration.  If the child elopes and frequently fails to return to the designated area, you may prefer to record how long the child remains away from where he should be.  If an adult consistently follows the child to direct him back, then it may make sense to record the frequency or rate of the behavior.

Here’s an example:

Eloping: Any instance of Bowie moving away from adult more than 5 ft while outside or inside without permission.

Examples Include:

  • Going across the room when directed to go to the table.
  • Going down the hall toward the big clinic room when directed to go to the bathroom.

Non-Examples Include:

  • Going across the room to get a toy from the shelf during choice time.
  • Running in circles around the structure in the Motor Room during choice time.

Operational Definition of Tantrum

Tantrums are common of young children although they can be difficult to define because, like aggression and SIB, they include multiple behaviors in one.  Any time you define a behavior that encompasses more than one behavior, consider the need to also define each of the behaviors separately.   

Defining these behaviors can become cumbersome and confusing.  If you record data for a behavior in a grouped behavior, that behavior should not be recorded individually as well.  That can skew the data making it appear that the behavior occurs more frequently than it actually does.

Take a look at this definition:

Tantrum: Any instance in which Petra engages in 2 or more of the following behaviors at the same time: crying (vocalizations louder than normal speaking voice lasting longer than 3 seconds with tears), throwing (moving objects not intended to be thrown through space farther than 3 ft), banging floor (using any part of the body or an object to make contact with the floor with sufficient force to make a sound), screaming (vocalizations louder than normal speaking voice lasting longer than 3 seconds without tears), hitting (making forceful physical contact using one or both hands with another person with sufficient force to make a sound or leave a mark), and/or flopping (going limp resulting in the body in a kneeling or lying flat on the floor position).

Examples Include:

  • Crying and flopping in response to a demand to transition.
  • Screaming and throwing materials on the floor when given a task demand.

Non-Examples Include:

  • Crying and laying on the floor in response to injuring herself.
  • Stomping her feet and throwing a ball in the gross motor room as part of play.

Operational Definition of Crying/Screaming

Many children cry for a variety of different reasons and there may not be a need to intervene.  However, some children may cry or combine crying with screaming to an excessive extent.  When defining a behavior that is either developmentally or often contextually appropriate, consider including parameters that allow for those instances to be excluded from the definition.

Here’s an example, but you may need to exclude a wider range of contextually appropriate crying depending on your specific situation:

Crying/Screaming: Any instance in which Christopher engages in a vocalization louder than is used for communication for longer than 3 seconds during which time he may or may not produce tears.

Examples Include:

  • Loud vocalizations accompanied with tears when presented with a task demand.
  • Loud vocalizations not accompanied by tears when told he could not have the iPad.

Non-Examples Include:

  • Laughing/giggling.
  • Crying as a result of hurting himself.

Onset: 30 seconds of occurrence

Offset: 30 seconds of nonoccurrence

*Note that onset and offset have been included in this definition as it’s a behavior that doesn’t have a clear start and stop so would likely be recorded using duration recording.

Operational Definition of Swearing

It’s almost universally accepted that young children should not swear, but what words constitute a swear?  When defining this behavior, you must be clear about which words are included or excluded from the definition.  This may vary between different contexts, but that would be confusing to the interventionist.  You should make the definition fit the strictest environment. 

Over time, you may be able to target the behavior at different levels for different contexts depending on the child’s ability to discriminate between contexts.  This would require clear guidelines for both the child and the interventionist.

Here’s an example:

Swearing:  Any instance in which Jack uses language inappropriate to a particular environment.


  • Swearing (saying “sh..” or “fu..”) while in the clinic room or hallway.
  • Swearing (saying “sh..” or “fu..”) while in a public location such as the library or Walmart.


  • Saying words staff do not approve of that are not included in the specified list.
  • Saying variations of the words included in the list (i.e. “shoot,” “fudge,” “darn,” etc.).

Operational Definition of Throwing

Throwing may seem straightforward, yet at what point does the behavior go from “pushing” or “displacing” an object to actually “throwing?”  Make sure this is clear in your definition.  Will sliding an object across a table be part of your definition?  At what point does the behavior become problematic and meet your criteria for intervention?

Look at this example:

Throwing:  Any instance in which Junior moves objects not intended to be thrown through space farther than one foot using any part of his body.

Examples Include:

  • Pushing items off a shelf or table.
  • Throwing a marker farther than one foot.
  • Kicking a bucket resulting in the items in the bucket being dumped on the floor.
  • Holding an inset puzzle upside down while standing resulting in the pieces being dumped on the floor.

Non-Examples Include:

  • Turning an inset puzzle upside down over a table prior to completing the puzzle resulting in one or more pieces falling on the floor.
  • Kicking or throwing a ball in the gross motor space.

Operational Definitions of Behavior

Clear operational definitions ensure accurate data collection and implementation of interventions.  As interventionists ask for clarification or make errors, hone your definitions to be clearer by including more examples and non-examples or by including more detail.  Your definitions should leave no question about whether the behavior occurs or not in any given moment.

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