Association Rules

An association rule simply states that there exists a statistical relationship between two or more items in a data set. An item is a literal or attribute value pair occurring in the data set. This relationship is generally shown in the form X $\Rightarrow$ Y where X and Y are sets of items. The statistic measures commonly used with association rules are confidence and support. Support is the percentage of the data instances containing both X and Y. Confidence is the percentage of instances containing X that also contain Y.