​What are the advantages and disadvantages of experimental studies and correlational studies? What might prompt a researcher to choose a correlational design over an experimental design?

A. Experimental studies
1. Have the advantage of yielding information about causal relationships, a type of information that no other single method has the power to show.
2. Have the disadvantages of being difficult to conduct and somewhat artificial because experiments require the manipulation of independent variables and the control of all other variables, which includes appropriate control group (or groups).
B. Correlational studies
1. Have the advantage of yielding information about the degree and direction of relationships between variables.
2. Have the disadvantage of being incapable of revealing causal relationships.
C. Researchers can make the choice of correlation over experimental method because
1. Some variables cannot be manipulated as part of an experiment due to ethical or practical problems in performing the manipulation. If a researcher had an interest in such variables, that researcher would have to choose another method of investigation.
2. Some research is designed to reveal strength of relationships between variables, which makes correlational research the best choice.