How big a deal is replication failure?

From Jason Mitchell at Harvard:

Recent hand-wringing over failed replications in social psychology is largely pointless, because unsuccessful experiments have no meaningful scientific value.

Because experiments can be undermined by a vast number of practical mistakes, the likeliest explanation for any failed replication will always be that the replicator bungled something along the way. Unless direct replications are conducted by flawless experimenters, nothing interesting can be learned from them.

Three standard rejoinders to this critique are considered and rejected. Despite claims to the contrary, failed replications do not provide meaningful information if they closely follow original methodology; they do not necessarily identify effects that may be too small or flimsy to be worth studying; and they cannot contribute to a cumulative understanding of scientific phenomena.

Replication efforts appear to reflect strong prior expectations that published findings are not reliable, and as such, do not constitute scientific output.

The field of social psychology can be improved, but not by the publication of negative findings.   Experimenters should be encouraged to restrict their “degrees of freedom,” for example, by specifying designs in advance.

Whether they mean to or not, authors and editors of failed replications are publicly impugning the scientific integrity of their colleagues. Targets of failed replications are justifiably upset, particularly given the inadequate basis for replicators’ extraordinary claims.

The full piece is here, I don’t quite buy it but a useful counter-tonic to a lot of current rhetoric.  I found this in my Twitter feed, but I forget whom to thank, sorry!

Addendum: An MR reader sends along this related argument.


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