Discontinuous Measurement in ABA: A Simple Guide (With Examples)

If you’re working in ABA therapy or studying for your RBT exam, you’ve probably heard about discontinuous measurement. But what exactly is it, and when should you use it?

In this easy-to-understand guide, we’ll explain:

• What discontinuous measurement is
• The different types you need to know
• When to use each method
• Practice questions with detailed answers

What is Discontinuous Measurement?

Discontinuous measurement means you don’t record every single instance of a behavior. Instead, you take samples or estimate how often a behavior occurs.

Why use it?
✔ Quicker than continuous measurement
✔ Good for busy classrooms or group settings
✔ Works well for behaviors that last a long time

Downside?
✖ Less precise than continuous measurement

Types of Discontinuous Measurement

1. Partial Interval Recording

What it is: Mark if the behavior happens at any time during the interval.
Best for: Behaviors you want to decrease (like tantrums or aggression).

📌 Example:
In a 10-minute session divided into 1-minute intervals, a child hits at 0:30 and 1:45. You’d mark “YES” for both intervals.

✅ Records: Whether behavior occurred at all in the interval

2. Whole Interval Recording

What it is: Only mark “YES” if the behavior lasts the entire interval.
Best for: Behaviors you want to increase (like staying seated).

📌 Example:
For 2-minute intervals, a child sits quietly from 0:00-2:00 but gets up at 3:30. Only the first interval counts.

✅ Records: Behavior that continues without stopping

3. Momentary Time Sampling

What it is: Check only at the very end of the interval.
Best for: When you can’t watch constantly (like in a busy classroom).

📌 Example:
Every 5 minutes, you look up. If the child is screaming when you check, mark “YES.”

✅ Records: Behavior happening at that exact moment

Practice Questions & Answers

Question 1:

Using partial interval recording (30-second intervals), a child hits at 0:10, 0:55, and 1:20. How many intervals get marked “YES”?

✅ Answer: 2 intervals (First hit is in Interval 1, second and third are both in Interval 2)

Question 2:

For whole interval recording (1-minute intervals), a child sits from 0:00-0:58 but stands at 0:59. Does this interval count?

✅ Answer: No (They didn’t sit the whole minute)

Question 3:

Using momentary time sampling (5-minute checks), you see screaming at 5:00 and 15:00 but not at 10:00. What’s the recorded data?

✅ Answer: “YES” at 5:00 and 15:00, “NO” at 10:00

When to Use Each Type

Final Tips for RBTs

1. Partial interval overestimates behavior
2. Whole interval underestimates behavior
3. Momentary sampling is easiest but least accurate

Need more help? Check out our free RBT study guide!