Starting with the ABC's of ABA

Starting with the ABC's of ABA Melinda Henson

Supporting files

The science of Applied Behavior Analysis tells us that behavior is lawfully related to its environment and the effects of that behavior on that environment.  In this context, “behavior” refers to actions or skills.  “Environment” includes any influence that might change or be changed by behavior.  In other words, when presented with a stimulus, we act based upon our history of reinforcement and punishment.  How many times have we heard that behavior (both positive and negative) is a form of communication?  Since we know that, how do we determine exactly what is being communicated? 

Functional Behavior Assessments or Descriptive Assessments are intended to tell us the “why” of behavior. The use of A(ntecedent)- B(ehavior)- C(onsequence) charts and checklists can be helpful tools when collecting information during direct observations.  There are many versions of these forms, but all should include opportunities to record the setting location, the antecedents (events which occurred immediately before behavior), a description of the observed behavior, and the consequences (simply put- what happened after the behavior?).  A-B-C data should be collected until a pattern is identifiable, typically with at least 10-15 separate instances recorded.  The pattern of Antecedents and Consequences gives us a hypothesis about the function of challenging behavior. 


When identifying Antecedents, be sure to ask the “Wh” questions:

  • Where?
  • With whom?
  • When?
  • What activity?
  • What are other students doing?
  • What is the teacher doing?

While also considering possible environmental contributing factors:

  • Staff
  • Proximity of others
  • Noise level
  • Group size

Or more distant setting events:

  • Medication changes
  • Changes or distress in home life
  • Health status of student


Before beginning to record data, you should have a clear and concise operationally defined target behavior.  This means that each behavior topography is described with clear parameters for what is considered an occurrence.  It is often very helpful to include examples and non-examples of behavior following the definition.


When identifying consequences, things may not be as clear as one event following a behavior.  Instead, multiple events may follow the behavior of concern (for example- adult provided attention and then removed or modified a task).  This is one reason that recording multiple occurrences of ABC data is required, so that the patterns can be evaluated for its influence on behavior while strengthening the confidence in the hypothesis.

Function of Behavior

Behavior occurs for a reason! The function of a behavior refers to the source of environmental reinforcement (events that maintain or increase the likelihood of behavior occurring).

A handy acronym to remember the 4 main functions of behavior is “Everybody EATS

= Escape or avoidance
A = Attention
T = Tangibles or Activities
S = Sensory Stimulation

Once the function of behavior is identified, it is time to begin planning behavior support strategies! When moving forward, it is crucial to remember the essential components of a Behavior Support Plan:

  • Behavior definitions and data-based decision making
  • Preventative strategies
  • Teaching & reinforcing replacement behavior(s)
  • Reinforcement contingencies
  • Reactive strategies

With a firm understanding of behavior and reinforcement contingencies in place, the Behavior Support Plan is ready for the team to implement, collect data, and analyze!