Leverage of an Association Rule

Properties2

Type	Concept
Note created	Feb 17, 2025

When working with association rules, the leverage metric computes the difference between the observed frequency of an antecedent set and consequent set appearing together and the frequency that would be expected if they were independent. It is derived from the support as:

$$\text{leverage}(A\to C)=\text{support}(A\to C)-\text{support}(A)\times \text{support}(C)$$

It lies in the $[-1,1]$ interval and a leverage value of 0 indicates independence.