The (relative) support of a rule "Item B Follows from Item A" is calculated as follows:
Support (A —> B) = (Number of transactions that contain items A and B) / all transactions.
The rule support from A —> B is the probability that items A and B appear together in a transaction. The greater the rule support is, the more frequently are items A and b sold together.
This key figure can take values between 0 and 1.
Note
The following applies: Support (A —> B) = Support (B —> A). Together with the relative support of the premiss and conclusion, this key figure forms the basis for almost all objective interestingness measures of a rule (lift, confidence, conviction,...).
Available as of Release | BI_CONT 703 SP09 |
|---|---|
Aggregation | No |
Exception Aggregation | No |
Calculation | See above |
Restriction | No |