Coefficient of Variation

Standard deviation has little interpretable meaning on its own unless the mean value is also reported alongwith. For a given standard deviation value, it indicates a high or low degree of variability only in relation to the mean value. For this reason, it is easier to get an idea of variability in a distribution by dividing the standard deviation with the mean. If this is then represented as a % of mean, it is called as coefficient of variation (cv) and algebraically is

cv = 100 * (s/x_mean).

Where - s is the standard deviation; and x_mean is the mean value.

Coefficient of variation is particularly useful when comparing dispersion in datasets with:

(i) Markedly different means, or,
(ii) Different units of measurement.

See Also:

standard deviation, variance

References:

Frank, H. and Althoen, S.C. "The coefficient of variation." §C.4.b in Statistics: Concepts and Applications Cambridge, Great Britain: Cambridge University Press, pp. 58-59, 1995.

Cite This As:

Dogra, Shaillay K., "Coefficient of Variation." From QSARWorld--A Strand Life Sciences Web Resource.
http://www.qsarworld.com/qsar-statistics-coeff-variance.php