When a behavior is noted only at the end of an interval, which observational method is being used?

The correct answer is momentary time sampling, which is a method used in observational behavior analysis where a designated observer notes whether a behavior is occurring at specific moments in time, typically at the end of predetermined intervals. This approach allows the observer to capture instances of the behavior without the need for continuous observation throughout the entire interval.

In momentary time sampling, data is collected by observing and recording the presence or absence of behavior at the very end of each set time period. This can provide valuable insights into the behavior's occurrence without being overly intrusive or time-consuming, making it easier to manage while still obtaining reliable data.

The other observational methods differ in how they record behavior occurrence. Whole interval recording requires that the behavior occur for the entire duration of the interval to be counted, while partial interval recording captures whether the behavior occurred at any point during the interval. Frequency count simply measures the total number of occurrences of a behavior over a specified timeframe and does not rely on set intervals for observation.