Dynamic assessment of relevancy in a case-based reasoner

The authors demonstrate techniques used in the HYPO program for representing and applying knowledge in the form of real and hypothetical cases to assist an attorney in evaluating and making legal arguments about a fact situation. To perform this task, indexing and retrieval of relevant cases are not enough. HYPO needs to know how to make factual comparisons of the cases relative to the facts and what the legal significance of those comparisons are in terms of arguments about the facts. HYPO uses the mechanism of claim-lattices. A claim-lattice projects the fact situation through the case knowledge base to create a neighborhood of cases surrounding the current fact situation in which the above comparisons become explicit. The authors present a detailed example of a claim-lattice actually generated by HYPO to analyze a real legal case