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  "body": "\n## Summary\n\nThe sign test is a [[hypothesis test|087P03NEND]] about the [[median|07Y2E7P9NP]] of a distribution, or about the median difference within matched pairs.\nIt uses only whether each observation lies above or below the hypothesised median.\nSo under the null hypothesis the count of observations above has a [[binomial distribution|0WCWA1KT3M]] with success probability $1/2$.\nIt needs almost no assumptions on the shape of the distribution, which makes it one of the simplest tests of [[nonparametric statistics|VFAJ1EG3X5]].\n\n## Explanations\n\n### L1 human\n\nSuppose a claim says that half of all values lie above $10$.\nLook at a sample and count how many values are above $10$.\nIf the claim is true, each value is above $10$ with chance one half, like a fair coin toss.\nTen values out of ten above $10$ would be like ten heads in a row, which has chance $1/1024$, so the claim looks doubtful.\n",
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