Which research approach is the most appropriate to establish a relationship that is causal in nature?

The experimental approach is most appropriate for establishing a genuinely causal relationship.

Causal-comparative research compares existing groups after the fact and cannot manipulate the cause.

Correlational research measures association between variables but cannot prove causation.

Descriptive research portrays characteristics and does not test cause-and-effect at all.

Experiments manipulate an independent variable while controlling extraneous factors.

Random assignment to conditions is what gives the experiment its causal power.