DRAGEN Academy · Free lesson · Parents, teachers, technicians · 8 minutes
How to take ABC data.
What it is. ABC data is a three-column note you write each time a behavior happens: what came right before it (the Antecedent), what the person did (the Behavior), and what happened right after (the Consequence).
Why it matters. You cannot change a behavior you cannot describe. Ten honest ABC lines tell a team more than a month of “he has been having a hard time.” Every behavior plan, every functional assessment and every good school meeting starts with this sheet.
The method
How to do it yourself: eight steps, one sheet.
- Pick one behavior and define it so a stranger could spot it. Not “aggression” — “open- or closed-hand contact with another person, hard enough to hear.” Not “meltdown” — “drops to the floor and screams for longer than ten seconds.” Write the definition at the top of the sheet.
- Set the sheet up before the day starts. Time, place, who was there, A, B, C, and a box for how long or how many. Print the one at the bottom of this page.
- When it happens, handle the moment first and write second. Within five minutes, while it is fresh. Tomorrow’s memory is a story, not data.
- Antecedent is the thirty seconds before. Who was there, what was asked, what was taken away, what was going on (noise, hunger, a transition). Facts only. “He was frustrated” is a guess. “I said ‘time for bath’” is a fact.
- Behavior is what you saw and heard. Count it or time it. “Screamed, about two minutes.” “Hit three times.”
- Consequence is what happened in the thirty seconds after — especially what people did. “I said ‘no hitting’ and picked him up” counts. “Nothing” is almost never true; write what actually happened, even if it was you giving in.
- Collect at least ten instances, or five days, before you look for a pattern. Three lines is a bad week, not information.
- Then read down the columns, not across. Does the same antecedent keep appearing? Does the same consequence? That repeat is your first clue to what the behavior is for — the next lesson, on function, takes it from there.
Worked example
Mia, age six, and the floor.
Behavior, defined: drops to the floor and screams for longer than ten seconds. Five entries from one week:
| When, where | A — right before | B — what happened | C — what happened next |
|---|---|---|---|
| Mon 7:40, hallway | Mom: “Shoes on, we’re leaving.” | Floor, screamed ~2 min | Mom put her shoes on for her |
| Mon 5:30, kitchen | Dad: “Bath time.” | Floor, screamed ~4 min | Dad: “Fine, five more minutes.” Bath was later |
| Tue 7:35, hallway | Mom: “Shoes.” | Floor, screamed ~1 min | Mom put her shoes on for her |
| Wed 12:10, kitchen | “Come sit at the table.” | Floor, screamed ~3 min | Lunch brought to the couch |
| Wed 7:00, bedroom | Dad: “Pajamas.” | Floor, screamed ~2 min | Dad dressed her on the floor |
Mistakes to avoid
Where good sheets go wrong.
- Writing feelings instead of facts (“he was being defiant”). Write what was said and done.
- Logging only the bad days. The quiet days tell you what was different.
- Stopping after three entries because a pattern “seems obvious.”
- Defining the behavior as a label (“meltdown,” “attitude”) so two adults log two different things.
- Changing what you do mid-week without writing that down too. Change is fine; unrecorded change wrecks the sheet.
Try it
One question, then the answer.
Which of these belongs in the A column? (a) “He was frustrated.” (b) “I said ‘time for bath.’” (c) “He always does this at night.”
Show the answer, and why
(b). It is something a stranger in the room could have heard. (a) is a guess about a feeling, and (c) is a claim about a pattern, not one instance. The pattern is what you find after ten honest lines like (b).
Something to keep
The ABC data sheet.
One page. Define the behavior at the top, then one line per instance. Ten lines or five days before you read it.
DRAGEN Academy · ABC data sheet · dragen.cloud
| Behavior, defined so a stranger could spot it: | |
|---|---|
| Date, time, where, who | A — the 30 seconds before (facts) | B — what I saw and heard (how long / how many) | C — what happened in the 30 seconds after |
|---|---|---|---|
Print shows only the sheet, in black on white. Nothing you write on it is sent anywhere; the page has no forms.
Where DRAGEN helps
Log it in one tap, see the graph.
The DRAGENfamily hub records what you see at home as it happens and draws the last two weeks as a graph. The paper sheet above works without it — the hub just means the sheet is never in the wrong bag.
Source
Where this comes from.
Bijou, Peterson & Ault (1968) introduced ABC recording in the Journal of Applied Behavior Analysis. The method as taught today: Cooper, Heron & Heward, Applied Behavior Analysis (3rd ed., 2020), the chapter on functional behavior assessment.
Examples on this page are made up. They contain no client, student or family information. This lesson teaches a method; it does not replace your child’s care team, your BCBA, or your payer’s written rules.