Legal Expert Systems: The Inadequacy of a Rule-Based Approach

The two different categories of legal AI system are described, and legal analysis systems are chosen as objects of study. So-called judgment machines are discussed, but it is decided that research in legal AI systems would be best carried-out in the area of legal expert systems. A model of legal reasoning is adopted, and two different methods of legal knowledge representation are examined: rule-based systems and case-based systems. It is argued that a rule-based approach to legal expert systems is inadequate given the requirements of lawyers and the nature of legal reasoning about cases. A new, eclectic approach is proposed, incorporating both rule-based and case-based knowledge representation. It is claimed that such an approach can form the basis of an effective and useful legal expert system.