A collection of one or more items
Example: {Milk, Bread, Diaper}
k-itemset
An itemsetthat contains k items
Support count (σ)
–Frequency of occurrence of an itemset
–E.g. σ({Milk, Bread, Diaper}) = 2
Support (ตัววัดประสิทธิภาพสาหรับสินค้า (item))
–Fraction of transactions that contain an itemset
–E.g. s({Milk, Bread, Diaper}) = 2/5
Frequent Itemset
–An itemset whose support is greater than or equal to a minsupthreshold