Summary: Duration is how long a behavior lasts, start to finish. Latency is how long it takes the behavior to begin after a cue. Both are timing measures, but they're answering different questions, and the exam loves to see whether you can tell them apart. This page walks through when to reach for each one, how to record them without messing up your data, and the traps that catch new RBTs.
Frequency tells you how often something happens. Sometimes that's not the question. If a kid has one tantrum a day but it runs forty minutes, "one per day" hides the whole problem. That's where duration and latency come in. Both measure time, but they clock different things, and knowing which one fits the goal is half the battle.
Duration: how long the behavior lasts
Duration is the running time of a behavior from the moment it starts to the moment it stops. You start the clock when the behavior begins and stop it when the behavior ends. The number you write down is in seconds, minutes, or whatever unit fits.
Reach for duration when the length of the behavior is the thing that matters clinically. Frequency wouldn't capture it. A few examples where duration is the right call:
- On-task behavior during independent work
- Length of tantrum episodes
- Time spent in stereotypy
- Independent play
- Sleep
That's the free preview of Duration and Latency. The complete guide, plus all 851 practice questions and 3 full exams, is in the study pack and the book.