How do natural experiments differ from laboratory experiments?

How do natural experiments differ from laboratory experiments?

• A. The independent variable is manipulated by the researcher
• B. The independent variable changes naturally, not manipulated by the researcher
• C. They require random assignment of participants
• D. The study uses natural changes in the IV and there is no random assignment

Answer: (D)

Natural experiments study causal effects when the researcher doesn’t manipulate the IV; instead, the IV changes due to natural or external factors. Because the assignment to different levels of the IV isn’t random and isn’t controlled by the researcher, there’s no random assignment involved. This combination—the IV changing naturally and no random allocation—best captures how natural experiments differ from laboratory experiments, where the researcher actively manipulates the IV and assigns participants to conditions to control for confounds. The other statements either suggest manipulation by the researcher or imply random assignment, which doesn’t fit the natural, quasi-experimental design.

Natural experiments study causal effects when the researcher doesn’t manipulate the IV; instead, the IV changes due to natural or external factors. Because the assignment to different levels of the IV isn’t random and isn’t controlled by the researcher, there’s no random assignment involved. This combination—the IV changing naturally and no random allocation—best captures how natural experiments differ from laboratory experiments, where the researcher actively manipulates the IV and assigns participants to conditions to control for confounds. The other statements either suggest manipulation by the researcher or imply random assignment, which doesn’t fit the natural, quasi-experimental design.