What defines a field experiment?

A field experiment is characterized by its use of natural environments to manipulate and measure variables. This approach allows researchers to investigate behavior in real-world settings, which enhances the generalizability of the results compared to a controlled lab environment. In a field experiment, participants are often unaware they are part of a study, which minimizes biases that can occur when individuals know they are being observed.

The choice that states it is conducted in a controlled environment lacks the essential feature of field experiments, as these typically involve real-world conditions rather than artificial settings. The reliance on participant surveys is not a defining characteristic of field experiments, as they can involve various methods of data collection beyond surveys. Lastly, analyzing data only after the study has concluded is common in many research methods, not specific to field experiments. In essence, the correct answer highlights the distinct nature of field experiments in utilizing real-life contexts for experimental research.