Which measurement method tends to underestimate the frequency of behavior when using whole-interval recording?

• A. Whole-interval recording.
• B. Partial-interval recording.
• C. Momentary time sampling.
• D. Event recording

Answer: (A)

When using whole-interval recording, you only note the target behavior if it lasts for the entire interval. Because many occurrences occur for only part of the interval, this method misses those partial events, causing the recorded frequency to be lower than the actual frequency. This underestimation becomes more pronounced when the behavior is brief or sporadic. In contrast, partial-interval recording tends to overestimate frequency by marking an interval if the behavior occurs at any moment, momentary time sampling provides a rough snapshot at the end of each interval, and event recording counts every occurrence directly. So, whole-interval recording tends to underestimate the frequency.