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Ethical Advocate for Accurate Application & Dissemination of Behavior Analysis

Antecedents - Behavior - Consequence (ABC's)

Descriptive Assessment is intended to help us determine why a behavior occurs rather than how often a behavior occurs.  Both are important questions to ask and to answer, but for the purposes of understanding under which conditions the behavior occurs, descriptive data is the best route.

The use of A[ntecedent]-B[ehavior]-C[onsequence] charts and checklists can be helpful tools for collecting information when conducting direct observations.  The form that is used (albeit a blank piece of paper) should include: 1) name or initials of the student (protect confidentiality), 2) the target behavior and definition, and 3) the setting location of the observation.  When completing this tool, identify the antecedents [events which precede] and consequences [events which follow] the target behavior of concern.  A-B-C data should be collected until a pattern is identifiable, typically with no fewer than 10-12 separate instances. 


When identifying the antecedents, consider these questions:

-  Where does the behavior happen?

-  With whom does the behavior occur?

-  When does the behavior happen?

-  What activity is the behavior occurring during?

-  What are other students doing when the behavior begins?

-  What are other teachers/adults doing when the behavior begins?

It is also helpful to consider possible contributing factors, such as:

* Specific staff

* Proximity of others

* Noise level in the classroom

* Number of individuals in the area

* Other environmental conditions: lighting, door (open/closed), noise in hallway, etc. 

Additionally, it is valuable to take into account distant antecedents/setting events such as:

~ Medication changes

~ Family/Home Variables (e.g. visiting family members, divorce, birth of a sibling, etc.)

~ Current health status of the student


Even though you should have a clear, operationally defined target behavior with examples and non-examples, it is important to record as much information about the behavior of concern during your observations.  Rather than writing, "aggressed", your notes may be enhanced by more detail, such as, "kicked peer", "hit teacher with fist", "pinched peer's arm".

Operationally defined target behaviors should be described as clearly and concisely as possible.  For the purposes of the example below:

Aggression is defined as any instance in which Kali's hands, feet, body, or objects come in contact with another person in a forcible way out of the context of the activity.  Example:  Kali hurls a book toward a peer.  Non-example: Kali throws a basketball toward a peer during Gym.


When identifying consequences, it may not be as clear as "time out", "reprimand" or "ignore".  Often times when observing behavior one may find that multiple events will follow the behavior of concern. All behavior should be recorded and evaluated for its influence on the target behavior.

For more information on ABC's

ABC Chart - This link will provide you access to a copy of a blank ABC chart.  To download an ABC checklist, visit the Downloads page on this site.

Applied Behavior Analysis for Teachers (8th Edition) - This widely-adopted introductory text presents behavior analysis principles hand-in-hand with a wealth of examples showing their practical classroom applications. To give students a better understanding of how behavior analysis actually works, the sequence of chapters follows that of an actual behavior analysis project; and actual data recording sheets, charts, and tables are provided in the text. The fictional "Professor Grundy" helps keep material lively and relevant by responding to objections to behavior modification, using shaping techniques in his own classroom, and instructing students in writing behavioral objectives.