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  "body": "\n## Summary\n\nInformation geometry studies families of [[probability distributions|0DVDCMA2DK]] as manifolds, using the tools of differential geometry.\nThe central structure is the Fisher information metric, a [[Riemannian metric|Q61VFHCH2J]] on the parameter space, together with a family of [[affine connections|JX65KSVHSJ]] called the $\\alpha$-connections.\nOn finite sample spaces, Chentsov's theorem shows that the Fisher metric is, up to a constant factor, the only metric invariant under sufficient statistics.\nThe field was developed largely by Shun-ichi Amari and has applications in statistics, machine learning and information theory.\n\n## Explanations\n\n### L1 human\n\nA statistical model is a family of distributions described by a few parameters, like the mean and standard deviation of a normal distribution.\nEach choice of parameters is a point, so the model is a space of points.\nInformation geometry measures the distance between two nearby points by how easily data can tell the two distributions apart.\nFor normal distributions, two distributions with means $0$ and $1$ are far apart when the standard deviation is small and close when it is large.\nWith this distance the family of normal distributions becomes a copy of the hyperbolic plane.\n",
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