What is momentary time sampling and what does it approximate?

• A. Momentary time sampling records whether the behavior is occurring at the end of each interval; approximates occurrence rate.
• B. Records the number of times the behavior occurs per minute.
• C. Records duration of behavior.
• D. Records whether behavior occurred anytime during interval.

Answer: (A)

Momentary time sampling checks the target behavior at the end of each interval and records whether it is occurring at that exact moment. By tallying these end-point checks across many intervals, you obtain the proportion of intervals in which the behavior was present, which serves as an approximation of the occurrence rate (the percent of time or intervals with the behavior). This method doesn’t capture how long the behavior lasts within an interval or how many times it happens inside the interval; it only notes presence at the end points. It differs from whole-interval sampling, which requires the behavior to occur for the entire interval to count, and from partial-interval sampling, which records if the behavior occurred at any time during the interval. It also isn’t a pure frequency count of every instance, nor a direct measure of duration.