Market-basket analysis (along with clustering) is an undirected data miningoperation, seeking patterns that were previously unknown. This makes it a form ofknowledge discovery. Market-basket analysis begins with categorizing customerpurchase behavior. The next step is to identify actionable information improvingprofit by purchase profile. Once profitability by purchase profile is known, retailershave factual data that can be used for key decision making. Laying out retail storesby purchase categories is referred to as affinity positioning