Lying with Statistics: the Sharpshooter & Post-hoc Fallacies

targetI’m not an expert at archery, but there’s a way I can guarantee I get a bull’s eye every time. It’s simple. I shoot the arrow at a large target, one I can’t possibly miss. Then, I walk up and draw a bull’s eye around the arrow.

We laugh at how ridiculous this is, but this sort of error occurs every day in peer reviewed studies published in prestigious journals. Called the Sharpshooter Fallacy, it’s all too common, so it’s important that we be able to recognize it.

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