3 ms·
The original assumption before Daniels was that the data would follow a normal distribution and so there was an "average" pilot. He showed that was wrong.
by dgemm 11y ago
The original assumption before Daniels was that the data would follow a normal distribution and so there was an "average" pilot.
He showed that was wrong.
- thaumasiotes 11y agoI can't tell what you mean. In some sense (not a very good one), the data must follow a normal distribution, as the sum of normal distributions is itself a normal distribution. But that would imply that you could sensibly add values like "circumference of upper arm" and "length, ankle to knee", which you really shouldn't be doing. - If you measure values from a 10-dimensional space, what would it mean for them to be "normally distributed"? Do we norm them by distance to the center of the space, or what? Does that approach preserve the nice properties of normals? - If this concept exists, did Daniels or anyone related to the project know that? Is it really what they were looking for? - If this concept exists, were the pilots in fact normally distributed? Saying "the data should follow a normal distribution" without having a definition of "normal distribution" that allows for multidimensional points immediately implies that all body measurements are correlated with all other body measurements at plus or minus 1, which I'm certain nobody believed. And the individual measurements are normally distributed.
- JupiterMoon 11y agoI this case they may not have been. Given the US Airforce was selecting pilots with measurements within certain bounds their measurements were probably a truncated normal.
- eru 11y agoYou are looking for https://en.wikipedia.org/wiki/Multivariate_normal_distribution https://en.wikipedia.org/wiki/Multivariate_normal_distributi...