Keep in mind that characteristics are attributes, not entities.

CharacteristicSpecification/CharacteristicValue

The fourth technique, typing, is a variant of the bottom up technique. This technique involves moving attributes and relationships from one or more subclasses and to their intermediate super-class and by adding an attribute that indicates what “type” of subclass is represented by an instance of the super-class.

Sub-typing (sub-classing) is one of the two ways that the Information Framework provides an extensible information model. The other way is the use of modeling patterns.

EntitySpecification/Entity, Entity/EntityRole, and the CharacteristicSpecification/CharacteristicValue

Appendix A The Information Framework (SID) and Object-Oriented Databases

• Update anomaly • Insert anomaly

Chapter 2 Implementing Information Framework (SID) Patterns

Chapter 4 Maintaining Information Framework (SID) Conformance