Lift Metric

INFO

Assesses how much more likely a rule-based association is to occur compared to a random occurrence.

How It Works

For a rule $X\to Y$:

$$\text{Lift}(X\to Y)=\frac{\text{Support}(X\cup Y)}{\text{Support}(X)\cdot \text{Support}(Y)}$$

• Measures how much more likely $Y$ is to occur when $X$ occurs
• Lift > 1: Positive association
• Lift = 1: Independent
• Lift < 1: Negative association

What to Look For

• Lift > 1 indicates meaningful association
• Helps filter out spurious rules
• Use alongside confidence for stronger rule validation

Application Models

• Apriori Algorithm
• Frequent Pattern Growth