ARM Advanced Settings

From Easyrec Wiki
Jump to: navigation, search

Beside the two parameters support and confidence additional metrics for measuring the importance of rules are provided. The following metrics are currently available:

  • lift
  • conviction
  • long tail correlation (ltc)

Lift and conviction are standard metrics, describing the interestingness of a rule. ltc is an experimental SAT made metric, describing the capacity of a rule <math>X \rightarrow Y</math> that a common item X refers to a rare item Y. ltc is defined as

<math>ltc(X \rightarrow Y) = support(X) * \log( \frac{support(X)}{support(Y)} )</math>

and has the following characteristics:

  • ltc(X->Y) < 0: X is the rare item, pointing to a common item Y.
  • ltc(X->Y) = 0: X and Y have are equal popular
  • ltc(X->Y) > 0: A common item X is referring to a rare item Y.

Currently these parameters can only be activated in the configuraton file .... When activated, these values replace the 'confidence' measure as the quality criteria!

Personal tools

easyrec documentation