ABC data
ABC data record the antecedent (what happened just before), the behavior, and the consequence (what happened just after) for each occurrence of a target behavior.
ABC recording is a descriptive assessment method. Each time the target behavior occurs, the observer writes down the antecedent, a description of the behavior itself, and the consequence. In the narrative format, the observer writes brief, objective descriptions in each column. In the structured (checklist) format, the observer checks preset categories, such as "demand given", "attention diverted" or "item removed", which is faster and easier to summarize.
Collected over many occurrences, ABC data can reveal patterns. If a client's crying usually follows being told to stop playing and usually ends with the toy being returned, that pattern suggests a hypothesis for the supervisor to consider. The data can also show times, people or activities associated with the behavior.
Good ABC data are objective and specific: "Teacher said 'Put your book away'" rather than "Teacher upset the student", and "Client threw the book on the floor" rather than "Client got mad". They are written as soon as possible, not reconstructed at the end of the day. ABC data show what tends to occur together, not what causes the behavior, so the RBT records and reports and the supervisor interprets.
Example and non-example
| Example | Antecedent: caregiver turns off the TV. Behavior: client drops to the floor and screams for 2 minutes. Consequence: caregiver turns the TV back on. |
|---|---|
| Non-example | "Client had a meltdown because they were tired" is not ABC data; it gives an interpretation instead of an observable antecedent, behavior and consequence. |
Don't confuse it with
| Scatterplot | ABC data record what happened before and after each occurrence; a scatterplot records only when behavior occurred across time blocks. |
|---|---|
| Three-term contingency | ABC data are a recording method; the three-term contingency is the conceptual unit (antecedent, behavior, consequence) that the method is based on. |
Test yourself
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Question 1An RBT is recording ABC data at a client's home. Which antecedent entry is written in observable terms?
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C: The caregiver said, "Bath time," and turned off the TV. The entry describes exactly what happened just before the behavior: what the caregiver said and did.
- A: This states an effect on the client's feelings, not what the caregiver did.
- B: This is a guess about what the client wanted.
- D: A "bad mood" is an inferred state, not an observable event.
Task A.5 · 40-hour curriculum section C
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Question 2Which ABC consequence entry describes what happened without interpreting it?
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A: The teacher said, "Stop that," and moved the chair. This reports what the teacher said and did. Words like "reinforced" or "punished" describe an effect on future behavior, which a single observation cannot show.
- B: Punishment is defined by a decrease in future behavior, which cannot be known from one event.
- C: Reinforcement is defined by an increase in future behavior, which cannot be known from one event.
- D: "Gave in" is an interpretation, not a description of what the teacher did.
Task A.5 · 40-hour curriculum section C
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Question 3An RBT observes a student during normal classroom routines and records what happens immediately before and after each instance of yelling, without changing anything in the classroom. Which type of functional assessment is this?
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B: Descriptive assessment. Directly observing behavior in the natural setting and recording antecedents and consequences without changing them is descriptive assessment.
- A: Indirect assessment uses interviews or rating scales, not direct observation.
- C: A functional analysis deliberately arranges antecedents and consequences.
- D: A reinforcer assessment tests whether items increase behavior when delivered contingently.
Task B.3 · 40-hour curriculum section D
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On the RBT exam
This term belongs to task B.3 Functional assessment in content area B, Behavior Assessment, which is 8 of the 75 scored questions.