Open texture and ontologies in legal information systems

The problem of open texture is long established in legal information systems. It is pervasive and needs to be addressed by any system able to deal with cases which are not entirely straightforward. Many systems have tried to deal with this problem, and normally they are divided into rule based, case based and statistical approaches. We look at these systems from a different perspective, that of ontologies. We first say what ontologies and open texture are. Next we review a range of approaches to open texture, and the domain conceptualisations which underlie them. We then discuss two ontologies which have been proposed for use in legal information systems, with particular reference to their treatment of open texture. Finally we identify a number of choices, which help determine the approach to open texture, and which are orthogonal to the particular representation technique used