Editing Contingency table (section)

{{short description|Table that displays the frequency of variables}}
{{For|cross-tabulation that aggregates by summing, averaging, etc. (rather than only by counting)|Pivot table}}
In [[statistics]], a '''contingency table''' (also known as a '''cross tabulation''' or '''crosstab''') is a type of [[table (information)|table]] in a [[matrix (mathematics)|matrix]] format that displays the multivariate [[frequency distribution]] of the variables. They are heavily used in survey research, business intelligence, engineering, and scientific research. They provide a basic picture of the interrelation between two variables and can help find interactions between them. The term ''contingency table'' was first used by [[Karl Pearson]] in "On the Theory of Contingency and Its Relation to Association and Normal Correlation",<ref>{{cite book|title=Mathematical contributions to the theory of evolution|publisher=Dulau and Co.|author=Karl Pearson, F.R.S.|date=1904|url=https://archive.org/details/cu31924003064833}}</ref> part of the ''[[Worshipful Company of Drapers|Drapers' Company]] Research Memoirs Biometric Series I'' published in 1904.

A crucial problem of [[multivariate statistics]] is finding the (direct-)dependence structure underlying the variables contained in high-dimensional contingency tables. If some of the [[conditional independence]]s are revealed, then  even the storage of the data can be done in a smarter way (see Lauritzen (2002)). In order to do this one can use [[information theory]] concepts, which gain the information only from the distribution of probability, which can be expressed easily from the contingency table by the relative frequencies.

A [[pivot table]] is a way to create contingency tables using spreadsheet software.