*Choose Index below for a list of all words and phrases defined in this glossary.*

**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, http://www.isixsigma.com/index.php?option=com_glossary *

Data Quality Glossary. A free resource from GRC Data Intelligence. For comments, questions or feedback: dqglossary@grcdi.nl