Market-basket analysis refers to methodologies studying the composition of a shopping basket of products purchased during a single shopping event. This technique has been widely applied to grocery store operations (as well as other retailing operations, to include restaurants). Market basked data in its rawest form would be the transactional list of purchases by customer, indicating only the items purchased together (with their prices). This data is challenging because of a number of aspects:A very large number of records (often millions of transactions per day)Sparseness (each market basket contains only a small portion of items carried)Heterogeneity (those with different tastes tend to purchase a specific subset of items)