Perhaps the most common data mining task is that of classification. Examples of classification tasks may be found in nearly every field of endeavor:
In classification, there is a target categorical variable, (e.g., income bracket), which is partitioned into predetermined classes or categories, such as high income, middle income, and low income. The data mining model examines a large set of records, each record containing information on the target variable as well as a set of input or predictor variables. For example, consider the excerpt from a data set shown in Table 10.1. Suppose that the researcher would like to be able to classify the income bracket of persons not currently in the database, based on the other characteristics associated with that person, such as age, gender, and occupation. This task is a classification task, very nicely suited to data mining methods and techniques.