ABC data

ABC data is a running record kept each time a behavior happens. The A is the antecedent, meaning what happened right before. The B is the behavior, described in plain terms anyone watching could see. The C is the consequence, meaning what happened right after, including what adults did. People watch and write things down without changing anything, which makes ABC data a descriptive assessment.

ABC notes feed into a functional behavior assessment (FBA), which works out why a behavior happens. On their own, they show what tends to go along with a behavior, not what causes it. And since notes are made only when the behavior happens, they can't show how often the same triggers come up without it. Your child's behavior analyst designs and reads these records, and behavior technicians help collect them.

You or your child's teacher may be asked to jot down ABCs at home or school. A note might read: "Asked to put on shoes, threw a shoe and cried, adult put the shoes away." Write what you saw and heard, not why you think it happened. Your child's behavior analyst then uses the notes as a starting point.

• What to write down: Ask your Board Certified Behavior Analyst (BCBA) for a simple form, an example of how to describe the behavior and whether to log meltdowns the same way.
• How the notes get used: Ask how your notes fit into the FBA, what else the team will look at and whether you'll go over them in parent training.
• What the notes show: Ask what patterns the team found and how sure they are about the cause.