FORMAL METHODS IN CIS: HETEROGENEOUS DATABASES GUEST EDITORS' INTRODUCTION

Abstract

There has been much progress recently in cooperative information systems: new problems are being attacked, new techniques are being developed. As the field matures and as its applications become deployed in a wider range of domains and locales, there is increasing interest in formal methods to understand, analyze, design, verify, and validate cooperative information systems. Since the science of cooperative information systems (CIS) unabashedly borrows from several traditional disciplines, the techniques and formal methods that it applies are also of a wide variety. This issue presents some of the best papers in this subfield of CIS. These papers are unified by their relationship to heterogeneous databases and information environments. Even within this subset of CIS, it is interesting to see methods whose traditional counterparts are in artificial intelligence, software engineering, and database semantics and query processing. Lee, Madnick, and Siegel address one of the fundamental problems in CIS, namely, that of the semantic interoperability of information systems that arise in different contexts. Context is the holy grail of a number of sciences that deal with meaning. This paper proposes an approach that has many useful properties for enabling the exchange of information among diverse data sources. It models context and interoperation at the knowledge level, term coined by Allen Newell in artificial intelligence; it uses techniques pioneered by Ray Reiter, also in artificial intelligence. This enables an abstract characterization of the meaning of information independent of its specific realization in a particular system. Lee and Wu also concern themselves with the interoperability of autonomous databases. They propose hyperrelations—extended from the relations of traditional database theory—as a uniform and succinct means to represent the local schemas