Module II of VI · Free, no account needed
The ABC model in your living room
Three letters and a fridge notepad turn "he does it for no reason" into a pattern you can actually see.
Part 1 Read: the idea
You now know that behavior has a job. The ABC model is the tool that finds it. Every behavioral moment, sweet or hard, has three parts, and once you can name them, chaos starts to look like a pattern.
- A is for Antecedent: what happened right before the behavior. The demand you gave, the word you said, the toy that got taken, the transition that started. Antecedents are the setup: the conditions the behavior shows up under.
- B is for Behavior: what your child actually did, in the plain, countable language you practiced in Module 1. "Threw the cup twice," not "lost it."
- C is for Consequence: what happened right after. In everyday speech, consequence means punishment. In ABA it means neither good nor bad: simply whatever followed. A scolding is a consequence. So is getting the tablet back, and so is the whole room going quiet.
The model’s big claim is that the consequence is usually what keeps the behavior alive. Behaviors that produce nothing tend to fade; behaviors that reliably produce something (an exit, an audience, an item, a feeling) get repeated. That means the payoff is often hiding in plain sight, in the thirty seconds after the behavior. It also means well-meaning responses can be doing the maintaining. "Fine, five more minutes" delivered mid-protest is a consequence. So is a long, heartfelt talk about why we don’t scream.
The fridge-notepad ABC log
You don’t need software or a clinic for this. Stick a notepad on the fridge, or open a note on your phone, with three columns: A, B, C. Each time the one behavior you’re tracking happens, jot a single line afterward, not during. Keep each column to a phrase: "Told him tablet time was over" / "screamed and gripped the tablet" / "I let him finish the video." The whole entry takes ten seconds. No analysis yet, no motive-words, just camera facts.
One entry proves nothing. A single incident could be a bad nap, a skipped snack, plain coincidence. But by the third or fourth entry on the same behavior, read your log top to bottom and hunt for repeats. Does the A column keep saying some version of "I ended something fun"? Does the C column keep ending with the fun continuing? When the same consequence shows up across three or more incidents, you’ve found the behavior’s likely function: the job from Module 1, now with evidence. Until then, your only assignment is to write the lines. The log does the thinking.
Part 2 Check your understanding
Five questions on the reading: three recall, two that ask you to apply the idea. Answers are graded right here on the page, and nothing is recorded.
Recall1. In the ABC model, what does "consequence" mean?
In ABA, consequence just means "what came next." A scolding, a returned tablet, or the room going quiet all count; the word carries no judgment about whether the outcome was pleasant or intended.
Recall2. According to the reading, which part of the ABC usually keeps a behavior alive?
Behaviors that produce nothing tend to fade; behaviors that reliably produce something get repeated. The payoff hiding in the thirty seconds after the behavior is what maintains it.
Recall3. How does the reading say to keep a home ABC log?
The log is deliberately tiny: three phrases, ten seconds, written afterward. Logging during the episode splits your attention, and long entries full of motive-words hide the pattern the log exists to reveal.
Apply it4. Every night, Jonah whines and climbs out of bed at lights-out. Each time, his mom lies down next to him "just for a minute" — which becomes twenty. The whining is now nightly. Using ABC, what is most likely maintaining the behavior?
Look at what follows the whining every single night: extended one-on-one closeness. That consequence is the likely engine. The bedtime hour might need attention too, but the reliably repeated payoff is what the model points to first.
Apply it5. A dad logs four incidents of his daughter shoving her plate away at dinner. His A column reads: "served a new food," "put a vegetable on her plate," "new recipe night," "served leftovers she hadn’t tried." His C column reads: "made her a quesadilla" every time. What has the log revealed?
Three or more matching incidents turn guesses into evidence. Here the A column repeats (unfamiliar food) and the C column repeats (a preferred food appears), pointing to a tangible function. The log can’t diagnose anything medical; it reveals patterns, and this one is clear.
Part 3 Watch it done
An ABC log earns its keep in the reading-back, and that’s a skill of its own: sitting down after the storm and letting the columns speak. In the scene below, a tablet handoff goes sideways for the third time in a week. You’ll see one incident live, and then something more useful: two parents at the kitchen table afterward, walking the notepad together, A to B to C, out loud. Neither of them planned the consequence they’re about to discover. Almost no parent does. The payoff crept in one reasonable-sounding compromise at a time, which is exactly why it takes a written log to see it.
As you watch, track three things: what happens in the seconds right after the scream (who bends, and what the bending buys); how the parents describe the incidents at the table, in camera facts with no motive-words and no blame in either direction; and the moment the C column repeats across all three entries, when the function stops being a guess. Notice, too, what they don’t do. Tonight is for seeing the pattern, not for fixing it mid-episode.
Video in production
This scene is being filmed with a BCBA-coached professional actor. Until it's live, the full script is below. Read it like a storyboard.
“The tablet handoff”
A living room, 7:30 on a school night. NOAH, 7, is on the couch with a tablet. PRIYA (parent) stands nearby; SAM (co-parent) is loading the dishwasher within earshot. A notepad hangs on the fridge.
- PRIYA
- Noah, two more minutes, then the tablet goes on the charger.
- ◦
- Two minutes later, Priya holds out her hand. Noah yanks the tablet to his chest, screams "NO!", and turns his back to her.
- PRIYA
- (calm, tired) Okay — one more video, and then it’s really done.
- ◦
- Noah quiets instantly. Ten minutes later he hands the tablet over without a word. Later, kids in bed — Priya brings the fridge notepad to the kitchen table and sits with Sam.
- PRIYA
- Third one this week. Read it with me. A: I say tablet time is over and reach for it. Same trigger, all three nights.
- SAM
- B: scream, grab it back, turn away. Tuesday, Thursday, tonight. Practically word for word.
- PRIYA
- Now C. Tuesday I said one more video. Thursday you said "just finish your game." Tonight… one more video again. That was me.
- SAM
- (reading down the column) So every scream has bought about ten more minutes of tablet. The scream works. It’s the best tool he owns.
- PRIYA
- And we never decided that. It just happened, one "okay, fine" at a time. Three lines on a notepad and it’s staring right at us.
- SAM
- So its job is keeping the tablet. We don’t have to solve it at 7:30 tomorrow — but now we get to plan before 7:30, knowing what the scream is for.
What to watch for
- The consequence is easy to miss live: "one more video" sounds like a reasonable compromise, but the log shows it’s the scream’s reliable payoff.
- Both parents narrate in camera facts ("scream, grab it back, turn away") with no motive-words and no blaming each other for the entries in the C column.
- They read A, B, and C as columns across all three incidents, and the function only becomes clear at entry three: one incident alone proved nothing.
- They end by naming the function and planning ahead, not by punishing tonight’s episode or changing rules mid-scream.
Part 4 Check the scene
Five more, grounded in what you just watched (or read).
Recall1. What happened immediately after Noah screamed and grabbed the tablet back?
The scream was followed by "one more video": roughly ten more minutes of tablet. That immediate outcome, repeated across incidents, is exactly what the C column later revealed as the payoff.
Recall2. What pattern did Priya and Sam find when they read the notepad together?
Same antecedent (tablet time ends, hand reaches out), same behavior, and the same consequence every time: the handoff got delayed. Three matching lines turned a nightly mystery into a readable pattern.
Recall3. What did the parents decide to do with their discovery, right there at the table?
The log’s job is to reveal the function; the fix comes with planning, before the next 7:30, not with a mid-scream rule change or a late-night lecture.
Apply it4. Imagine tomorrow night Priya holds firm (no extra video) and Noah’s scream gets louder and longer than ever before. What is the most likely explanation?
When a behavior that has reliably worked suddenly stops working, it often gets briefly bigger before it fades: the child is pressing the button harder. The bump is common, temporary, and a sign the log read the function correctly.
Apply it5. Suppose the notepad’s C column had instead read: "I sat with him and rubbed his back until he calmed," all three nights, and the tablet still got handed over each time. What would that pattern suggest?
Same A, same B, but a different repeated consequence points to a different function. If screaming reliably produces one-on-one comfort rather than tablet time, attention becomes the working hypothesis. The C column, not the behavior itself, tells you the job.
Part 5 Now you do it!
Log three incidents of one behavior
- Choose exactly one behavior to track this week: the same recurring moment you’d most like to understand. Write it at the top of the log in observable words.
- Set up your log where you’ll actually use it: a notepad on the fridge or a note pinned on your phone, with three columns labeled A, B, C.
- Each time the behavior happens, wait until the episode ends, then write one line: a phrase for what came right before, a phrase for exactly what your child did, and a phrase for what happened right after, including what you did.
- Keep every entry in camera facts. If a motive-word sneaks in ("stubborn," "testing me"), cross it out and rewrite what a stranger would have seen.
- After the third entry, sit down (with a co-parent if you have one) and read each column top to bottom, out loud. Circle anything that repeats, especially in the C column.
- Write one sentence at the bottom: "The behavior reliably produces ______, so its function is probably ______." That sentence is what you’ll build on next.
🎥 Film the moment
The clip that matters is your child in the genuine situation, not a re-enactment or a recap to camera. Capture one of the three incidents you’re logging: the A (what set it off), the B (what your child did), and the C (what followed), all in one clip.
- Before: start rolling at the first sign of the trigger; the lead-up usually holds the answer.
- During: prop the phone and forget it; a steady, boring one-take of a real moment beats anything staged.
- After: keep rolling through what the behavior produces and how things settle. That's the part everyone stops filming too soon.
Real life comes first: never delay a response your child needs for the sake of footage, and don't film any moment where safety is in play.
Watch it back: self-review
Review your clip against this list. (Ticks live only on this page; a refresh clears them.)
📹 Optional: get this clip observed
When accounts launch, you'll be able to upload this footage (your child's real moment: before, during, and after) and a BCBA will write down what they observe in it: the lead-up, the behavior, what followed. No advice and no plan comes back, and the service runs on the same terms as video observation, which asks for the behavioral research permission rather than a fee. Genuine everyday footage is the only kind worth watching; staged demos and recap-to-camera videos can't be observed. Until our legal consent framework is published, uploads stay off.
Footage exactly like this is what the pay-for-data program will accept once it opens. It pays $10 per 15 usable minutes when you allow commercial use, and you can instead contribute to research alone, unpaid, if you would rather.
Saved, in this browser only. See your progress on the course page.