Which is an example of a field experiment?

In sociological research, a field experiment involves manipulating an independent variable in a natural environment rather than a controlled, laboratory setting. The correct choice reflects a study that fits this definition.

Rosenthal and Jacobson's labeling study, also known as the "Pygmalion in the Classroom" experiment, is indeed an example of a field experiment. It involved researchers observing the impact of teacher expectations on student performance in a real classroom setting. Through this study, they were able to assess how labeling students as 'high potential' or 'low potential' influenced their academic outcomes in a natural educational context, making it a demonstration of a field experiment where the manipulation occurred outside a laboratory framework.

In contrast, Milgram's obedience study and Zimbardo's prison experiment were conducted in highly controlled environments, making them more representative of laboratory experiments. Census data collection, while it involves systematic gathering of information, does not include manipulation of variables and therefore does not qualify as an experiment in the sociological sense.