Tier 3 · Intensive
Functional behaviour assessment (FBA)
A team process to figure out why a behaviour happens by gathering interviews, observations, and data.
How to do it
- Form a team: teacher, family, administrator, and a behaviour specialist or school psychologist.
- Define the target behaviour clearly and measurably.
- Gather information: records review, teacher and family interviews, and student interview when appropriate.
- Collect direct observation data (ABC logs) across several settings and days.
- Look for patterns: when, where, with whom, and what happens after.
- Write a hypothesis statement: “When [trigger], [student] will [behaviour] in order to [function].”
- Use the hypothesis to build a behaviour intervention plan.
Why it works
- Interventions that match the function of behaviour work far better
- Replaces guesswork with evidence
- Required in many situations for students with disabilities
When to use it
- Behaviour is persistent despite Tier 1 and Tier 2 supports
- Behaviour is dangerous or seriously disrupts learning
- When required by SEN/ASN procedures or school policy
Tips and pitfalls
- Follow your school’s procedures and consent requirements.
- Look for “setting events” too: sleep, hunger, medication changes, conflicts at home.
- An FBA is only useful if it leads to a plan.
Templates for this strategy
FBA interview and summary
Structured interview questions and a summary page with a hypothesis statement for a functional behaviour assessment.
FBA interview and summary.docxABC observation log
Record what happened before, during, and after each incident to find patterns and the likely function of the behaviour.
ABC observation log.docxFrequency tally sheet
Count how often a behaviour happens each day and period. Good for behaviours with a clear start and end, like calling out or hitting.
Frequency tally sheet.docxOn-task interval recording
Check whether the student is on task at regular intervals to measure engagement. Includes a peer comparison row.
On-task interval recording.docx