> A RCT does not establish causality. That's essentially my point. A single study/experiment never proofs causality. You need a theory to explain the causality and multiple studies that falsify other possible causality mechanisms.
This might be a good heuristic for assigning confidence to results, but in theory, an RCT absolutely does establish causality, assuming internal, external, construct, and statistical validity of the study.
Multiple studies may not be better than one good study (assuming the above), which can be tested by looking at the leverage in a meta-anlaysis.
Having a theory is kind of orthogonal to a study finding a true positive result. Almost every published study, true or false, invokes some kind of theory, true or false. There is a joke in the soft sciences along the lines that you make up a new theory for every study.
This might be a good heuristic for assigning confidence to results, but in theory, an RCT absolutely does establish causality, assuming internal, external, construct, and statistical validity of the study.
Multiple studies may not be better than one good study (assuming the above), which can be tested by looking at the leverage in a meta-anlaysis.
Having a theory is kind of orthogonal to a study finding a true positive result. Almost every published study, true or false, invokes some kind of theory, true or false. There is a joke in the soft sciences along the lines that you make up a new theory for every study.