covariance

[ koh-vair-ee-uhns ]

noun

, Statistics.

1. the expectation or mean value of the variable formed by multiplying the differences obtained by subtracting two given variates from their respective means; the product of the standard deviations of two given variates and the coefficient of correlation between them.

covariance

/ kəʊˈvɛərɪəns /

noun

1. statistics a measure of the association between two random variables, equal to the expected value of the product of the deviations from the mean of the two variables, and estimated by the sum of products of deviations from the sample mean for associated values of the two variables, divided by the number of sample points. Written as Cov ( X, Y )

Word History and Origins

Origin of covariance¹

First recorded in 1875–80; co- + variance

Example Sentences

"Eddy covariance towers are currently the gold standard for measuring canopy photosynthesis ," Wu explained.

From Science Daily

The eddy covariance stations consist of instruments and techniques for calculating the flux of trace gases, like water vapor, coming off the land surface.

From Science Daily

Metabolic covariance networks of Alzheimer's disease animal models showed a lower community structure agreement compared to normal models.

From Science Daily

By comparison with the covariance matrix C for the classical data, we see that the density matrix for the quantum version of the data actually is the covariance matrix, up to an overall factor.

From Nature

OrbFit gives root-mean-square uncertainties and the covariance matrix of the elements at the end of the fit; these results were used for the subsequent integrations.

From Nature