An ABC chart is a simple record of what happened before a behaviour (the antecedent), what the person did (the behaviour) and what happened straight afterwards (the consequence). It gives a behaviour support practitioner useful information, but it is not a functional behaviour assessment: it is one of the pieces of information an assessment draws on.
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Prepared by Trevor Keen Founder and Physiotherapist · Reviewed 11 November 2026 |
If you support someone with behaviours of concern, you may have been asked to "keep ABC notes". This guide shows how to write entries that are clear enough to use, with a made-up example, and explains where your notes fit in the bigger picture of a functional behaviour assessment (FBA) under positive behaviour support.
At a glance
| ✓ | A, B and C stand for antecedent (what happened just before), behaviour (what you saw and heard) and consequence (what happened just after). |
| ✓ | Write what you could see or hear, not what you think the person felt or why they did it. |
| ✓ | An ABC chart records patterns; it doesn't explain them. Working out the purpose of a behaviour is the job of an assessment. |
| ✓ | In the NDIS, only an NDIS behaviour support practitioner can do a functional behaviour assessment, but families, support workers and schools can help collect the data. |
| ✓ | If anyone is in immediate danger, keep them safe first and write notes later. |
In this guide
- What does an ABC chart show?
- How do you fill in an ABC chart?
- What does a good ABC entry look like? A fictional example
- Is an ABC chart the same as a functional behaviour assessment?
- Who can do an FBA, and what can families and support workers do?
- Common mistakes when keeping ABC notes
- Common questions
What does an ABC chart show?
An ABC chart is a table with a row for each time the behaviour happens. It lists the date and place, then three things: what was going on just before, what the person did, and what happened just after. The NDIS Quality and Safeguards Commission lists "antecedent, behaviour, consequence (ABC) data collection" as a direct assessment method, meaning information gathered by watching and recording what happens in real settings (NDIS Commission practice guide, Table 4).
Over several entries, patterns can show up: a particular place, a type of request, a time of day, or a response from other people that seems to go with the behaviour. Looking for these patterns is part of how a practitioner works out what a behaviour is for (NDIS Commission practice guide, section 15).
How do you fill in an ABC chart?
Keep each entry short, and write it soon after the event so you remember the details.
| 1 |
Note the date, time, place and who was there These details are often where the pattern is. "Tuesday, 3:40 pm, kitchen, two support workers" is more useful than "after school". |
| 2 |
A: what happened just before Write the observable event: a request, a change of plan, a noise, someone arriving or leaving. The Commission describes triggers as observable events, not internal states such as anxiety or a reference to a person's disability or diagnosis (practice guide, Table 6). |
| 3 |
B: what the person did Describe it so that someone who wasn't there could picture it: "hit the table with an open hand and said 'no, no, no'". |
| 4 |
C: what happened straight after Write what people did and what changed: "support worker left the room", "the TV was turned off", "he was given a drink". Write it neutrally, even if you wish you had responded differently. |
| 5 |
Add anything unusual about the day Poor sleep, pain, a change of staff or a different routine can make a behaviour more likely hours or days later. These background events (the Commission calls them setting events) usually don't show up in the A column, so give them their own notes line. |
The Commission's guidance is that behaviour should be described in "observable and measurable" terms, free from bias and judgement, and that words such as "meltdown" or "tantrum" are not used to describe the behaviour itself. It also says everyone involved should agree what the behaviour is and how it is described (practice guide, section 12). If several people are recording, agree the wording together first, so one person's "aggression" and another's "yelling" don't get mixed up.
What does a good ABC entry look like? A fictional example
The example below is made up to show the idea. It isn't a real person or a real case, and a real chart would have many more entries.
Fictional example: Alex, in a share house
| When and where | A: before | B: behaviour | C: after |
|---|---|---|---|
| Mon 4:10 pm, hallway | Support worker asked Alex to switch off the TV for dinner | Pushed the remote onto the floor, shouted "no", stood in the doorway | Support worker said dinner could wait 10 minutes and left the room |
| Wed 8:15 am, kitchen | Dishwasher started; several people talking at once | Put hands over ears, left the kitchen quickly, closed bedroom door | Left alone; came out 20 minutes later and ate breakfast |
| Fri 4:05 pm, hallway | Different support worker; asked Alex to switch off the TV for dinner | Pushed the remote onto the floor, shouted "no" | Support worker turned the TV off; Alex went to his room |
Look at the wording. "Pushed the remote onto the floor" can be seen and counted. "Had a meltdown because he was overwhelmed" mixes a label and a guess about feelings into the record, and two people could read it differently. The Commission's own examples make the same point: "slams bedroom door and yells" is observable, while "non-compliant" is not.
From these three rows you could notice that the TV request comes up twice and that noise comes up once. You couldn't say why it happens. That step needs more information, which is where the practitioner comes in.
Want a practitioner to look at your notes?
Our behaviour support team works with the person, their family and their supporters. The first call with our triage team is free, and we usually reply within 1 to 2 business days.
Book or referCall 08 8166 4700Is an ABC chart the same as a functional behaviour assessment?
No. Under the NDIS rules, a functional behaviour assessment is "the process for determining and understanding the function or purpose behind a person's behaviour". It may involve data, observations and other information, and the result is then placed in the wider context of the person's life (NDIS Commission, rules for specialist behaviour support providers). An ABC chart is one source of that data.
A practitioner combines it with other information, such as conversations with the person and the people around them, past reports, direct observation in everyday settings, questionnaires and reviews of other records (practice guide, tables 3 and 4). They then write a hypothesis about the function of the behaviour, which is a working explanation to be tested, not a certainty. The Commission adds that a diagnosis, or "power and control", shouldn't be described as the function of a behaviour.
Research points the same way. A 2023 study notes that results from descriptive assessments such as ABC records "vary in effectiveness and validity" (Tereshko and colleagues, Behavior Analysis in Practice, 2023), and a 2017 study of adults with severe intellectual disability recommended combining several assessment methods rather than relying on one (Delgado and colleagues, Frontiers in Psychology, 2017).
So your chart is valuable, but don't draw firm conclusions from a few entries or put a plan in place on that basis alone. Read more on our functional behaviour assessment page, and on how the findings become a behaviour support plan.
Who can do an FBA, and what can families and support workers do?
Under the NDIS, the assessment itself must be done by an NDIS behaviour support practitioner, someone the NDIS Commission considers suitable, working for a registered specialist behaviour support provider (practice guide, section 7). A comprehensive behaviour support plan has to be based on an assessment that includes an FBA (NDIS Commission, rules for specialist behaviour support providers).
Two cautions. First, safety comes before paperwork: if anyone is in immediate danger, keep people safe and call 000 if needed, then write notes afterwards. Second, an ABC chart is personal information. The Commission's guide says information gathered should be relevant to its purpose and respect the person's right to privacy, so keep charts secure and share them only with people the person and family have agreed to.
Common mistakes when keeping ABC notes
- Writing labels or guesses. "Angry", "attention-seeking" and "manipulative" describe an opinion, not what happened.
- Only recording the big events. Smaller, ordinary behaviours can show what comes before a bigger one. Ask your practitioner what to include.
- Leaving out the C. What people did afterwards, including what you did, is part of the picture. It isn't a judgement of anyone.
- Writing it all up at the end of the week. Detail fades quickly. A short note on your phone, written when things are calm, beats a long entry from memory.
You can also read more about what counts as a behaviour of concern, and why a behaviour is not the person.
Common questions
What does ABC stand for in behaviour support?
Antecedent, behaviour, consequence: what happened just before, what the person did, and what happened just after. It is a way of recording events so patterns can be seen over time.
How long should I keep an ABC chart?
It depends on the person and how often the behaviour happens, so ask the practitioner who will use it. The NDIS Commission expects practitioners to guide whoever is collecting data, so you shouldn't have to guess. We don't set a minimum recording period before the first appointment.
Do I need an ABC chart before I contact CHSA?
You can get in touch without one; the first call with our triage team is free. At the first appointment we'd like as much information as you have, so if you've kept recent ABC records or other notes, please share them.
Can a teacher or support worker fill in the chart?
Yes. Anyone who sees the behaviour can record it, as long as they use the same description of the behaviour. With consent, our practitioners can work with schools and support teams.
Is there an ABC chart template I can download?
We don't offer a downloadable template. The NDIS Commission does not prescribe particular assessment tools, and our practitioners can show you a format that suits the person.
Ready to talk about behaviour support?
Positive behaviour support at CHSA is funded through the NDIS. Send a referral or call us on 08 8166 4700, and bring any notes you have already kept.
Book or referSee our feesRelated reading
- Functional behaviour assessment: how it works
- Behaviours of concern: what they are and what helps
- Behaviour support plans
Prepared by
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Trevor Keen Founder, Conscious Healthcare SA · Physiotherapist (AHPRA PHY0002063374) · Master of Physiotherapy and Bachelor of Psychological Studies, Flinders University |
Trevor is a physiotherapist whose lived experience of disability led him to found CHSA, bringing psychology, assessments, occupational therapy, behaviour support and dietetics under one roof in Adelaide. He has completed a Bachelor of Psychological Studies at Flinders University, is now studying psychology at honours level, and helps write our guides alongside the clinicians who deliver each service.
Sources
- NDIS Quality and Safeguards Commission. (2026). Behaviour support assessment, including functional behaviour assessment: Practice guide (Version 1.0, April 2026). Primary source, read in full 11 Nov 2026. https://www.ndiscommission.gov.au/sites/default/files/2026-05/Behaviour-Support-Assessment-FBA-Guide-PDF.pdf (accessed 11 Nov 2026)
- NDIS Quality and Safeguards Commission. Rules for specialist behaviour support providers and NDIS behaviour support practitioners. Primary source (cites the NDIS (Restrictive Practices and Behaviour Support) Rules 2018, s 5 and s 20), read 11 Nov 2026 (accessed 11 Nov 2026)
- NDIS Quality and Safeguards Commission. How to develop behaviour support plans (updated 9 November 2026). Primary source, read 11 Nov 2026 (accessed 11 Nov 2026)
- Tereshko, L., Weiss, M. J., Harper, J., and Ross, R. K. (2023). Impact of a training package to improve the effectiveness of descriptive assessment data. Behavior Analysis in Practice. Peer-reviewed; abstract read via Europe PMC, full text not read (accessed 11 Nov 2026)
- Delgado, C., Gonzalez-Gordon, R. G., Aragon, E., and Navarro, J. I. (2017). Different methods for long-term systematic assessment of challenging behaviors in people with severe intellectual disability. Frontiers in Psychology. Peer-reviewed, open access; abstract read, full text not read (accessed 11 Nov 2026)
If you are in crisis or thinking about harming yourself, call 000 or Lifeline on 13 11 14.
This guide is general information, not advice about your situation. Speak with your GP or one of our team about what's right for you.
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