The Uni-Level Description: A Uniform Framework for Representing Information in Multiple Data Models Shawn Bowers and Lois M. L. Delcambre   View Paper (PDF)   Return to Systems and Data Integration Abstract One advantage of having several different representation schemes and data models is that users can select the right representation and associated tools for their particular need. However, multiple representations introduce structural, model-based heterogeneity, making it difficult to combine information from different sources and exploit information using generic tools (e.g., for querying or browsing). In this work, we define a uniform representation based on a meta-data-model called the Uni-Level Description (ULD) that can accommodate and accurately store information in a broad range of data models. The ULD defines three distinct instance-of relationships plus a relationship for modeling conformance, which is used to connect (data) constructs to other (schema) constructs and can be constrained to reflect the requirements of the data model. The ULD has been shown to enable powerful, generic transformation rules and simple generic browsing capability over information represented in diverse data models and representation schemes. ©2005 Association for Computing Machinery