Materialization: A Powerful and Ubiquitous Abstraction Pattern

Materialization is a useful abstraction pattern that can be identified in many application settings. Intuitively, materialization is the relationship between a class of categories (e.g., models of cars) and a class of more concrete objects (e.g., individual cars). This paper gives a quasi-formal semantic definition of materialization in terms of the usual is-a and isof abstractions, and of a class/metaclass correspondence. New and powerful inheritance mechanisms are associated with materialization. Examples, properties, and extensions of materialization are also presented. Providing materialization as an abstraction mechanism for conceptual modeling enhances expressiveness by a controled introduction of classification at the application level.