Which type of research is likely to provide the strongest evidence about the existence of cause-and-effect relationships?

Experimental research provides the strongest evidence about cause-and-effect relationships.

Non-experimental research observes without manipulation and cannot firmly establish causation.

Historical research reconstructs past events and cannot control variables for causal proof.

Descriptive research portrays current conditions without testing causal links.

Experiments combine manipulation of a cause with control and random assignment.

This design rules out most alternative explanations for an observed effect.