Editing Consistency (statistics) (section)

In [[statistics]], '''consistency''' of procedures, such as computing [[confidence interval]]s or conducting [[hypothesis test]]s, is a desired property of their behaviour as the number of items in the data set to which they are applied increases indefinitely. In particular, consistency requires that as the dataset size increases, the outcome of the procedure approaches the correct outcome.<ref name=Dodge>{{cite book |last=Dodge |first=Y. |year=2003 |title=The Oxford Dictionary of Statistical Terms |publisher=OUP |isbn=0-19-920613-9 }} (entries for consistency, consistent estimator, consistent test)</ref>
Use of the term in statistics derives from Sir [[Ronald Fisher]] in 1922.<ref>{{cite book |last1=Upton |first1=G. |last2=Cook |first2=I. |year=2006 |title=Oxford Dictionary of Statistics |edition=2nd |publisher=OUP |isbn=978-0-19-954145-4 }}</ref>

Use of the terms ''consistency'' and ''consistent'' in statistics is restricted to cases where essentially the same procedure can be applied to any number of data items. In complicated applications of statistics, there may be several ways in which the number of data items may grow. For example, records for rainfall within an area might increase in three ways: records for additional time periods; records for additional sites with a fixed area; records for extra sites obtained by extending the size of the area. In such cases, the property of consistency may be limited to one or more of the possible ways a sample size can grow.