DIC Reduce number of scans ABCD Once both a and d are determined frequent, the counting of Ad begins ABC ABD ACD BCD Once all length-2 subsets of BCD are determined frequent, the counting of BCD begins AB ACBC IADBD CD Transactions 1-itemsets ABCD Apriori 2-itemsets Itemset lattice 1-itemsets S. BrinR. Motwani,j UlIman 2-items and s. tsur. dynamic itemset DIC --.-----3-items counting and implication rules for market basket data. In SIGMOD 97 February 4, 2021 Data Mining: Concepts and TechniquesFebruary 4, 2021 Data Mining: Concepts and Techniques 23 DIC: Reduce Number of Scans ABCD ABC ABD ACD BCD AB AC BC AD BD CD A B C D {} Itemset lattice ◼ Once both A and D are determined frequent, the counting of AD begins ◼ Once all length-2 subsets of BCD are determined frequent, the counting of BCD begins Transactions 1-itemsets 2-itemsets … Apriori 1-itemsets 2-items DIC 3-items S. Brin R. Motwani, J. Ullman, and S. Tsur. Dynamic itemset counting and implication rules for market basket data. In SIGMOD’97