Frequent Itemsets and Association rules Association Rules Finding Association Rules Question: " find all association rules with support 2 s and confidence≥c. Note: " support"of an association rule is the support of the set of items on the left Hard part: finding the frequent itemsets Note: if ( i, i,,i-j has high support and confidence, then both{i1,i2…,ik}and{i,i2… ik,) will be frequentFrequent Itemsets and Association Rules 14 Finding Association Rules ▪ Question: “find all association rules with support ≥ s and confidence ≥ c .” ▪ Note: “support” of an association rule is the support of the set of items on the left. ▪ Hard part: finding the frequent itemsets. ▪ Note: if {i1 , i2 ,…,ik } → j has high support and confidence, then both {i1 , i2 ,…,ik } and {i1 , i2 ,…,ik ,j } will be “frequent.” Association Rules