A. The minimal number of attributes necessary to support the data requirements of the enterprise.
B. Attributes with a close logical relationship (described as functional dependency) are found in the same relation.
B. Implementation of a method that depends on the type of the object it is applied to (overriding).
C. Minimal redundancy with each attribute represented only once with the important exception of attributes that form all or part of foreign keys, which are essential for the joining of related relations.