Data Mining: Concepts and Techniques, 3rd Edition

2.5 Summary

■ Data sets are made up of data objects. A data object represents an entity. Data objects are described by attributes. Attributes can be nominal, binary, ordinal, or numeric.

■ The values of a nominal (or categorical) attribute are symbols or names of things, where each value represents some kind of category, code, or state.

■ Binary attributes are nominal attributes with only two possible states (such as 1 and 0 or true and false). If the two states are equally important, the attribute is symmetric; otherwise it is asymmetric.

■ An ordinal attribute is an attribute with possible values that have a meaningful order or ranking among them, but the magnitude between successive values is not known.

■ A numeric attribute is quantitative ...