Summary: This page walks through the measurement systems you'll actually use on the job and see on the exam: continuous methods (event recording, duration, latency, IRT) and discontinuous methods (momentary time sampling, partial interval, whole interval), plus permanent product, ABC, scatterplot, and task analysis data. You'll learn what each one is good for, where it lies to you, and how to pick the right one for the behavior in front of you.
Data is how we know whether anything we do is working. Strip away the jargon and that's the whole game: you change something in the environment, you measure the behavior, and the data tell you whether to keep going or change course. A skilled RBT can run a beautiful session, but if the data are sloppy, the BCBA is making decisions on noise. So this stuff matters. Let's go through the methods you'll be expected to know and use.
Continuous measurement
Continuous measurement means you catch every single instance of the behavior during the observation period. Nothing slips by. It gives you the truest picture, and the price you pay is attention. You have to be watching the whole time, which is exactly why it isn't always practical.
Event recording
You count each time the behavior happens. That's it. A kid raises his hand four times, you write down four.
That's the free preview of Data Collection Methods. The complete guide, plus all 851 practice questions and 3 full exams, is in the study pack and the book.