>sampling bias debate reminds me of this stats legend from ww2: the USAF wanted to armor planes where the bullet holes were. statistician abe wald recommended a

>sampling bias debate reminds me of this stats legend from ww2: the USAF wanted to armor planes where the bullet holes were. statistician abe wald recommended armoring where the bullet holes weren't on the theory that those were the non-survivable hits It wasn't quite that simple, but the story has a gem of truth. As this article quotes Stephen Stigler (son of George Stigler who worked with Abraham Wald): >..."The military was inclined to provide protection for those parts that on returning planes showed the most hits. Wald assumed, on good evidence, that hits in combat were uniformly distributed over the planes. It follows that hits on the more vulnerable parts were less likely to be found on returning planes than hits on the less vulnerable parts, since planes receiving hits on the more vulnerable parts were less likely to return to provide data. From these premises, he devised methods for estimating vulnerability of various parts." http://www.ams.org/publicoutreach/feature-column/fc-2016-06 http://www.ams.org/publicoutreach/feature-column/fc-2016-06 This paper goes into detail for those interested in statistics: https://people.ucsc.edu/~msmangel/Wald.pdf https://people.ucsc.edu/~msmangel/Wald.pdf