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

**Poisson distribution** : A distribution of items that does not have a normal curve, rather the tail on one side of the curve is longer and less populated than the curve on the other side, as it true for a distribution of data records by frequency of error in each record.

[Category=Data Quality ]

*Source: Larry English, http://www.iaidq.com/main/glossary.shtml , 05-Feb-2009 10:41 *

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**Poisson distribution** - A discrete probability distribution that expresses the probability of a number of events occurring in a fixed time period if these events occur with a known average rate, and are independent of the time since the last event.

[Category=Quality ]

*Source: American Society for Quality, 11 October 2010 08:10:11, http://www.asq.org/glossary/ *

**Poisson distribution** - The Poisson Distribution is a discrete distribution which takes on the values X = 0, 1, 2, 3,... It is often used as a model for the number of events (such as the number of telephone calls at a business or the number of accidents at an intersection) in a specific time period. It is also useful in ecological studies, e.g., to model the number of prairie dogs found in a square mile of prairie.

The Poisson distribution is determined by one parameter, lambda. The distribution function for the Poisson distribution is f(x) = exp(-1*lambda) lambda^x / x!

[Category=Data Quality ]

*Source: iSixSigma, 11 February 2011 10:44:57, 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