Models for Metadata or Metamodels for Data?

In this paper we examine modeling and metamodeling for metadata. We illustrate the need of metamodeling through three examples where metadata sets are used to efficiently process internal functions. We show that several levels of metamodeling are required in order to efficiently support essential functions provided by these systems. We argue that extensible metadata managers should support (i) several modeling levels, (ii) homogeneous manipulation of these different levels and (iii) extensibility of the corresponding models and metamodels. We introduce a pyramid of modeling levels for extensible metadata managers and we propose conceptual graphs as a homogeneous modeling formalism for the different levels. Copyright 1997 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.