Support and Confidence Support count: The support count of an itemset X, denoted by X count, in a data set T is the number of transactions in t that contain X assume t has n transactions Then (X∪Y) count support= (X∪) count confidence Xcount10 Support and Confidence ◼ Support count: The support count of an itemset X, denoted by X.count, in a data set T is the number of transactions in T that contain X. Assume T has n transactions. ◼ Then, n X Y count support (  ). = X count X Y count confidence . (  ). =