Which method is likely to produce an underestimation of behavior occurrence during observations?

Whole interval recording is likely to produce an underestimation of behavior occurrence during observations because it involves recording whether a behavior occurred during the entire interval. If the behavior occurs only part of the time within that interval, it will not be counted as having occurred. This method requires that the behavior lasts for the entire duration of the interval to be recorded as present, which means that fleeting or intermittent behaviors may be missed. As a result, the overall frequency of those behaviors may be significantly underestimated because only those that occur for the full interval will be noted.

In contrast, frequency recording captures each instance of a behavior regardless of its duration, while duration recording measures the length of time a behavior lasts, allowing for a more accurate representation of the actual occurrences. Event recording simply tallies each instance of the behavior as it occurs, providing a straightforward count.