A Note on Covariance in Propagation of Uncertainty

Edwin F. Meyer
DePaul University, Chemistry Department, 1036 West Belden Avenue, Chicago, IL 60614-3214
J. Chem. Educ., 1997, 74 (11), p 1339
DOI: 10.1021/ed074p1339
Publication Date (Web): November 1, 1997

Abstract

It is pointed out that whenever both the slope and the intercept are used in calculating a physical quantity from a linear regression, propagation of error must include the covariance as well as the variances. The point is illustrated with a calculation of the boiling point of water from the parameters of the lnP vs 1/T fit. If the covariance is omitted from the propagation of error, the estimate of uncertainty is unreasonably large.

Keywords (Audience):

First-Year Undergraduate / General

Keywords (Subject):

Chemometrics

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  • Received: August 03, 2009

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