Daily Archives: October 2, 2018

Multiple Testing

Suppose I showed you a close-up, on a live video feed, of where my shot at a target landed. The video is zoomed in on the target’s bulls-eye, and lo and behold, right there is my shot. No doubt about it: bulls-eye. I brag about what a good shot I am, and you’re impressed.

Then my cat gets on the table and accidentally zooms the camera view out to show the entire target (a cat? maybe not an accident). Now you can see that I took about 300 shots, they landed all over the place (some even missed the target completely), and one of them hit the bulls-eye. My guess: you would no longer be so impressed. You might even think my original camera view was misleading.

That, in essence, is how people still buy and sell the misleading claim that there was a “pause/hiatus/slowdown” in global surface temperature during the early 2000s. Some, I’d even venture to say most, do it without knowing what they’re doing. Some who have done it but have been told why it’s a problem, persist in doing it still. The former I’d call an honest mistake; the latter I’d call not just misleading, but deliberate deception.

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