Lift
A metric in association rule mining that measures how much more likely two products are to be purchased together compared to chance.
Full Definition
In retail basket analysis, lift is calculated as the ratio of the observed support for a product pair to the expected support if the two products were purchased independently. A lift value greater than 1.0 indicates a positive association, meaning the products appear together more often than chance would predict. A lift of exactly 1.0 implies independence, and a value below 1.0 suggests a negative association. Lift is used alongside support and confidence to evaluate the strength and reliability of association rules. Editors must be careful not to confuse 'lift' in this statistical sense with 'sales lift,' which refers to incremental revenue attributed to a promotion.
Usage
Usage note: Always lowercase. When 'lift' appears in a retail analytics document, verify from context whether it denotes association rule lift or promotional sales lift, as both terms are common and frequently confused.
In Context
- "The product pair showed a lift of 3.4, indicating a strong cross-sell opportunity for the promotional campaign." — Market basket analysis report
- "Editors reviewing the analytics white paper must distinguish between 'lift' as a basket metric and 'sales lift' as a promotional measure." — Editorial style guide