Authors: Terry Halpin
Tags: 2005, conceptual modeling
Some information modeling approaches allow instances of relationships to be treated as entities in their own right. In the Unified Modeling Language (UML), this is called ‘reification’, and is mediated by association classes. In Object-Role Modeling (ORM), this is called ‘objectification’ or ‘nesting’. While this modeling option is rarely supported by industrial versions of Entity-Relationship Modeling (ER), some academic ER versions do support it. Objectification is related to the linguistic activity of nominalization, of which two flavors may be distinguished: circumstantial; and propositional. In practice, objectification is prone to misuse, and some modeling approaches provide incomplete or flawed support for it. This paper analyzes objectification in-depth, shedding new light on its fundamental nature, and providing practical guidelines on using objectification to model information. Because of its richer semantics, the main graphic notation used is that of ORM. However, the main ideas are relevant to UML and ER as well.Read the full paper here: https://www.emmsad.org/archive/2005
