causation

by

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.

Continue reading →

by

The Numbers Don’t Lie—Do They?

correlation chartDo any of these conclusions sound familiar? They’ve all appeared in the news at one time.

  • Children living near power lines have higher rates of leukemia; therefore, the electric field around the lines causes cancer.
  • Because the number of children diagnosed with autism has climbed at the same rate that the number of children receiving vaccines, we can conclude that vaccines cause autism.
  • The rise in global temperatures at the end of the 20th century is due to the increased use of fossil fuels in that same period.

Continue reading →