Final answer:
The observational study method of quantifying behavior by counting social interactions in a mall over a one-hour period is known as event sampling. It's a structured observational method that provides quantifiable data on the frequency of specific behaviors in a natural setting.
Step-by-step explanation:
In the observational study of adolescents at the mall, counting the number of social interaction behaviors that occur within a one-hour observation period is an example of the event sampling method of quantifying behavior. This type of structured observation allows researchers to record specific instances of behavior during a certain period. Observational studies are a type of nonexperimental scientific investigation where the researcher measures characteristics in a sample but does not attempt to manipulate the variables of interest.
Event sampling is particularly useful when the behavior being studied is frequent enough to count, but not so frequent that the researcher loses track. It provides concrete, quantifiable data that can be used to infer patterns of behavior in a natural setting, such as the mall in this scenario. Structured observation, like event sampling, is distinct from methods such as surveys or participant observation, where subjects might respond to questions or where researchers immerse themselves in a group to observe from an 'insider' perspective.