#Resource --- status: tags: image: time: aliases: --- # Abraham Wald: A Statistical Hero https://www.historyofdatascience.com/abraham-wald-a-statistical-hero/ During World War II, Wald’s skills were put to use on behalf of the war effort at the Statistical Research Group at Columbia University. One of his greatest and most famous contributions was to help the Allies figure out how to better-protect planes from enemy artillery. The dilemma was that adding armor to the plane also slowed it down and increased the fuel it consumed. The researchers needed to figure out where putting armor would have the greatest effect. Planes coming back from bombing campaigns were often riddled with bullet holes. While many reasoned that the armor should be focused on the areas of the plane where bullets tended to land the most, Wald suggested that they consider the areas of returning planes that bullets seemingly weren’t hitting, notably the engine. After all, the planes they were examining were only the ones that had survived — they weren’t looking at the ones that had been shot down. > “Wald’s maths-trained habits of thought brought him an insight the officers had missed. A mathematician is always asking, ‘What assumptions are you making? And are they justified?’ Once you recognize that you’ve been making assumptions, it can take just a moment to realize it’s wrong.” Jordan Ellenberg, American mathematician, discussing Wald’s work in World War II. What Wald was exposing was survivorship bias, or the tendency to focus on only a subset of people or things that have made it through a certain process. For example, a successful person or organization is often held up as evidence that their methods lead to success. What isn’t considered, however, are the many people who may have pursued the same methods but failed due to random events Beyond recognizing the flaws in the military’s evaluation of risks to bombers, Wald deployed sequential analysis to determine the best ways to protect planes from enemy fire. He and others who were involved in statistical analysis of war decisions helped lay the foundation for modern operational research, which large organizations of all kinds now use to increase efficiency, boost safety and reduce waste. # Tasks ```tasks path includes {{query.file.path}} not done ``` ---