In this paper we discuss the role of explicit specifications of domain conceptualisations - now popularly called "ontologies" - in legal information systems. We describe the advantages that accrue from producing an ontology for such systems, as well as the ontologies so far developed which are directed at the legal domain. We then illustrate how taking an ontological perspective can give insight into what is common and what is disparate in apparently different approaches. We conclude by offering some findings as to the nature of ontologies for legal information systems, and some ideas concerning the creation of a library of legal ontologies. 1. Introduction In the last five years there has been a growing recognition of the need to create explicit specifications of how knowledge in a domain is conceptualised. Such an explicit specification is now normally termed an "ontology" in the literature, following Gruber (1992). Whether this term is helpful or not - certainly it cannot be unders...

In this article we present a four-phased method for the development of legal knowledge systems.We set out from the well-studied CommonKADS method for the development of knowledge systems and tailor this method to the legal domain.In particular, we propose a generic legal ontology, and describe the creation of statute-specific ontologies to make the method more suitable for our purposes.In the construction of these ontologies we start from a theoretical analysis of the legal domain.The well-known example of the Imperial College Library Regulations (ICLR) is used to illustrate the method.