What method records the number of individuals engaged in a target response at the end of the recording interval?

The method that records the number of individuals engaged in a target response at the end of the recording interval is known as PLACHECK. PLACHECK, or "planned activity check," involves observing a group at a specific moment to count how many individuals are participating in the target behavior. This method is particularly useful in group settings, where the interest lies in understanding the distribution of behavior among participants at a particular time.

In this approach, the observer takes a snapshot of the group to determine how many members are engaged in the specific behavior of interest. This allows for an analysis of the group's engagement over time, as the data collected can show trends or changes in participation levels throughout different intervals.

Other recording methods, while valuable, serve different functions. For example, event recording counts each instance of a behavior as it occurs but does not specifically focus on group engagement at the end of an interval, instead capturing each occurrence in real-time. Time sampling and interval recording focus on the presence or absence of behavior within set time intervals but do not provide a count of how many individuals are engaged at a moment. Therefore, PLACHECK is uniquely suited for gathering data on group behavior participation in a concise manner.