My View on the Connection between Theory and Direct Replication

I loved Simine’s blog post on flukiness and I don’t want to hijack the comments section of her blog with my own diatribe. So here it goes…

I want to comment on the suggestion that researchers should propose an alternative theory to conduct a useful or meaningful close/exact/direct replication. In practice, I think most replicators draw on the same theory that original authors used for the original study.  Moreover, I worry that people making this argument (or even more extreme variants) sometimes get pretty darn close to equating a theory with a sort of religion.  As in, you have to truly believe (deep in your heart) the theory or else the attempt is not valid.  The point of a direct replication is to make sure the results of a particular method are robust and obtainable by independent researchers.

My take:

Original authors used Theory P to derive Prediction Q (If P then Q). This is the deep structure of the Introduction of their paper.  They then report evidence consistent with Q using a particular Method (M) in the Results section.

A replicator might find the theoretical reasoning more or less plausible but mostly just think it is a good idea to evaluate whether repeating M yields the same result (especially if the original study was underpowered).* The point of the replication is to redo M (and ideally improve on it using a larger N to generate more precise parameter estimates) to test Prediction Q.  Some people think this is a waste of time.  I do not.

I don’t see how what is inside the heads of the replicators in terms of their stance about Theory P or some other Theory X as relevant to this activity. However, I am totally into scenarios that approximate the notion of a critical test whereby we have two (or more) theories that make competing predictions about what should be observed.  I wish there were more cases like that to talk about.

* Yes, I know about the hair splitting diatribes people go through to argue that you literally cannot duplicate the exact same M to test the same prediction Q in a replication study (i.e., the replication is literally impossible argument). I find that argument simply unsatisfying. I worry that this kind of argument slides into some postmodernist view of the world  in which there is no point in doing empirical research (as I understand it).