Final answer:
The major advantage of the experimental method is that it allows researchers to establish cause-and-effect relationships between variables.
Step-by-step explanation:
The major advantage of the experimental method is that it allows researchers to establish cause-and-effect relationships between variables. By manipulating the independent variable and controlling extraneous variables, experimental research enables researchers to make causal statements about the effect of the independent variable on the dependent variable. This method is particularly useful in science as it provides a controlled environment for testing hypotheses and drawing conclusions.