Fisher information

noun

A measure of the amount of information that an observable random variable X carries about an unknown parameter θ of a distribution that models X. Formally, it is the variance of the score, or the expected value of the observed information.

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Meanings

nounFisher information (uncountable)
  1. uncountablemathematicsA measure of the amount of information that an observable random variable X carries about an unknown parameter θ of a distribution that models X. Formally, it is the variance of the score, or the expected value of the observed information.

Origin

Named after the statistician Ronald Fisher.

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Cite this entry
APA

Fisher information. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Fisher%20information

MLA

“Fisher information.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Fisher%20information. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Fisher information,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Fisher%20information.

Source: Fisher information on Wiktionary, CC BY-SA 4.0.