Package elki.itemsetmining.associationrules.interest
Much of the confusion with these measures arises from the anti-monotonicity of itemsets, which are omnipresent in the literature.
In the itemset notation, the itemset \(X\) denotes the set of matching transactions \(\{T|X\subseteq T\}\) that contain the itemset \(X\). If we enlarge \(Z=X\cup Y\), the resulting set shrinks: \(\{T|Z\subseteq T\}=\{T|X\subseteq T\}\cap\{T|Y\subseteq T\}\).
Because of this: \(\text{support}(X\cup Y) = P(X \cap Y)\) and \(\text{support}(X\cap Y) = P(X \cup Y)\). With "support" and "confidence", it is common to see the reversed semantics (the union on the constraints is the intersection on the matches, and conversely); with probabilities it is common to use "events" as in frequentist inference.
To make things worse, the "support" is sometimes in absolute (integer) counts, and sometimes used in a relative share.
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Interface Summary Interface Description InterestingnessMeasure Interface for interestingness measures. -
Class Summary Class Description AddedValue Added value (AV) interestingness measure: \( \text{confidence}(X \rightarrow Y) - \text{support}(Y) = P(Y|X)-P(Y) \).CertaintyFactor Certainty factor (CF; Loevinger) interestingness measure. \( \tfrac{\text{confidence}(X \rightarrow Y) - \text{support}(Y)}{\text{support}(\neg Y)} \).Confidence Confidence interestingness measure, \( \tfrac{\text{support}(X \cup Y)}{\text{support}(X)} = \tfrac{P(X \cap Y)}{P(X)}=P(Y|X) \).Conviction Conviction interestingness measure: \(\frac{P(X) P(\neg Y)}{P(X\cap\neg Y)}\).Cosine Cosine interestingness measure, \(\tfrac{\text{support}(A\cup B)}{\sqrt{\text{support}(A)\text{support}(B)}} =\tfrac{P(A\cap B)}{\sqrt{P(A)P(B)}}\).GiniIndex Gini-index based interestingness measure, using the weighted squared conditional probabilities compared to the non-conditional priors.Jaccard Jaccard interestingness measure:JMeasure J-Measure interestingness measure.Klosgen Klösgen interestingness measure.LaplaceCorrectedConfidence Laplace Corrected Confidence interestingness measure.Leverage Leverage interestingness measure.Lift Lift interestingness measure.OddsRatio Odds ratio interestingness measure.PhiCorrelationCoefficient Phi Correlation Coefficient interestingness measure.SebagSchonauer Sebag Schonauer interestingness measure.YulesQ Yule's Q interestingness measure.YulesY Yule's Y interestingness measure.