ABC: Antecedent, Behavior, Consequence

Overcoming Learning Disabilities With Behavior Modification

Boy in the car
mrs / Getty Images

Antecedent, Behavior, Consequence—also known as "ABC"—is a behavior-modification strategy often employed for students with learning disabilities, particularly those with autism. It can also be useful for nondisabled children as well. ABC uses scientifically-tested techniques to help guide students toward the desired outcome, whether that outcome is eliminating an undesirable behavior or promoting a beneficial behavior.

The History of ABC Modification

ABC falls under the umbrella of applied behavior analysis, which is based on the work of B.F. Skinner, the man often referred to as the father of behaviorism. In his theory of operant conditioning, Skinner developed a three-term contingency to shape behavior: stimulus, response, and reinforcement. 

ABC, which has become accepted as a best practice for evaluating challenging or difficult behavior, is almost identical to operant conditioning except that it frames the strategy in terms of education. Instead of the stimulus, there is an antecedent; instead of the response, there is a behavior; and instead of the reinforcement, there is a consequence.

The ABC Building Blocks

ABC offers parents, psychologists, and educators a systematic way in which to look at the antecedent or precipitating event or occurrence. The behavior is an action taken by the student that would be observable by two or more people, who would objectively be able to note the same behavior. The consequence might refer to removing the teacher or student from the immediate area, ignoring the behavior, or refocusing the student on another activity that hopefully won't be an antecedent for similar behavior.

To understand ABC, it's important to take a look at what the three terms mean and why they're important:

Antecedent: Also known as the "setting event," the antecedent refers to the action, event, or circumstance that led up to the behavior and encompasses anything that might contribute to the behavior. For example, the antecedent may be a request from a teacher, the presence of another person or student, or even a change in the environment.

Behavior: The behavior refers to what the student does in response to the antecedent and is sometimes referred to as "the behavior of interest" or "target behavior." The behavior is either pivotal—meaning it leads to other undesirable behaviors—a problem behavior that creates danger for the student or others, or a distracting behavior that removes the child from the instructional setting or prevents other students from receiving instruction. Note: A given behavior must be described with an "operational definition" that clearly delineates the topography or shape of the behavior in a way that makes it possible for two different observers to identify the same behavior.

Consequence: The consequence is an action or response that follows the behavior. A consequence, which is very similar to "reinforcement" in Skinner's theory of operant conditioning, is an outcome that reinforces the child's behavior or seeks to modify the behavior. While the consequence is not necessarily a punishment or disciplinary action, it can be. For example, if a child screams or throws a tantrum, the consequence may involve the adult (the parent or teacher) withdrawing from the area or having the student withdraw from the area, such as being given a timeout.

ABC Examples

In nearly all psychological or educational literature, ABC is explained or demonstrated using examples. This table illustrates examples of how a teacher, instructional assistant, or another adult might use ABC in an educational setting.

How to Use ABC




The student is given a bin filled with parts to assemble and asked to assemble the parts.

The student throws the bin with all the parts onto the floor.

The student is given a timeout until he calms down. (The student must later pick up the pieces before being allowed to return to classroom activities.)

The teacher asks a student to come to the board to move a magnetic marker.

The student bangs her head on the tray of her wheelchair.

The teacher attempts to soothe the student by redirecting the behavior with a preferred item, such as a favored toy.

The instructional assistant tells the student to clean up the blocks.

The student screams, “No, I won’t clean up!”

The instructional assistant ignores the child’s behavior and presents the student with another activity.


mla apa chicago
Your Citation
Webster, Jerry. "ABC: Antecedent, Behavior, Consequence." ThoughtCo, Aug. 28, 2020, Webster, Jerry. (2020, August 28). ABC: Antecedent, Behavior, Consequence. Retrieved from Webster, Jerry. "ABC: Antecedent, Behavior, Consequence." ThoughtCo. (accessed March 28, 2023).