Guest editorial 16th International Conference on Conceptual Modeling (ER'97)
The six papers in this issue of Data and Knowledge Engineering were chosen from among those presented at the 16th Int. Conf. on Conceptual Modeling (ER'97) in November, 1997. They represent some of the best work in this area as selected by the Program Committee chairs, based on input from the entire Program Committee and on feedback from the Editorial Board of Data and Knowledge Engineering. Authors were asked to submit a full journal-length paper expanding on their conference presentation and, where relevant, responding to issues raised by the audience. Each of these papers is not only interesting and informative in its own right, but together, they demonstrate the breadth and depth of current research in conceptual modeling.
ER'97 was held at UCLA, the site of the first ER Conference in 1979. This year's organizers made a conscious effort to broaden the scope of presentations in order to appeal to MIS practitioners as well as academic researchers in both computer science and information systems. This range is reflected in the papers selected for this issue. Authors of two of the papers are associated with MIS departments in schools of business, while the other four papers come from computer science departments. The ER Conferences have long had strong international participation. Submissions came from 24 different countries, and 18 countries were represented on the final program. The papers in this special issue came from five different countries.
The first four papers examine various issues related to database design. The last two deal with more operational concerns, querying uncertain data and consistency in rule-triggering systems.
'Deriving Semantic Information through Property Covering and Inheritance' by A. Analyti, N. Spyratos and P. Constantopoulos takes the covering relationship, which is well known in semantic and object-oriented data models, and applies it to properties rather than entity classes. Property covering is shown to lead to useful schema derivations.
'An Ontology-Based Expert System for Database Design' by V.C. Storey, D. Dey, H. Ullrich and S. Sundaresan describes an approach to enhancing the capability of expert systems used for database design. An ontology classifying terms dealing with database application areas can help the design system make intelligent suggestions concerning the content and structure of a design.
The framework presented in 'A General Formal Framework for Schema Transformation' by P. McBrien and A. Poulovassilis provides a consistent way to represent transformations used in various schema integration methodologies. In particular, the proposed framework makes it possible to identify transtbrmations that are valid only for certain instances of a schema.
'A Temporal Approach to Managing Schema Evolution in Object Database Systems' by I. Goralwalla, D. Szafron, M. Ozsu and R. Peters addresses another aspect of schema modification -the need to record the evolution of a schema through time.