Efficiently Finding Negative Association Rules Without Support Threshold

Typically association rule mining only considers positive frequent itemsets in rule generation, where rules involving only the presence of items are generated. In this paper we consider the complementary problem of negative association rule mining, which generates rules describing the absence of itemsets from transactions. We describe a new approach called MINR (Mining Interesting Negative Rules) to efficiently find all interesting negative association rules. Here we only consider the presence or absence of itemsets that are strongly associated. Our approach does not require a user defined support threshold, and is based on pruning items that occur together by coincidence. For every individual itemset we calculate two custom thresholds based on their support: the positive and negative chance thresholds. We compared our implementation against Pearson φ correlation.