A Level Psychology OCR Practice Exam

The chosen answer identifies field experiment as the method that does not fit into the category of non-experimental research methods. Field experiments involve manipulation of an independent variable in a natural setting, which allows researchers to establish cause-and-effect relationships. This differs from non-experimental methods, which do not involve manipulation and rely on observation or self-reporting data.

In contrast, self-report and observation are inherently non-experimental as they do not manipulate variables; instead, they gather data based on participants' responses or behaviors in their natural environment. Correlation, likewise, assesses the relationship between two variables without attempting to influence them, making it another form of non-experimental research.

Therefore, identifying field experiment as the method that is not non-experimental aligns with the definitions and characteristics of research methodologies, emphasizing the experimental control mandatory in field experiments.