Pooled Standard Deviation

Pooled Standard Deviation - Pooled standard deviation is the standard deviation remaining after removing the effect of special cause variation-such as geographic location or time of year. It is the average variation of your subgroups.

Pooled Standard Deviation combines two such deviations to then compare their statistical difference.

s = sqrt[((n1-1)s1^2 + (n2-1)s2^2)/(n1+n2-2)]

[Category=Data Quality ]

Source: iSixSigma, 11 February 2011 10:47:42, https:web.archive.org/web/20111109014246/http:www.isixsigma.com/index.php?option=com_glossary