Data Collection: No interesting patterns can be validly discovered without a set of historical data that is representative of the population of interest. Each observation in the historical data set should belong to exactly one of the predetermined classes. In direct marketing, such historical data is collected by observing the purchasing behaviours of customers from a previous campaign. Customers in the previous campaign may or may not have received the direct promotion. Whether a customer was to receive the direct promotion may have been randomly decided or by a data mining model. Each observation is associated with a number.
