Modeling Legal Argument Reasoning With Cases and Hypotheticals

• Authors: Kevin Ashley
• Venue: Modeling Legal Argument Reasoning With Cases and Hypotheticals
• Year: 1988

THIS DISSERTATION IS ABOUT ADVERSARIAL, CASE-BASED REASONING AND THE ''HYPO'' PROGRAM THAT PERFORMS ADVERSARIAL REASONING WITH CASES AND HYPOTHE- TICALS IN THE LEGAL DOMAIN. THE DISSERTATION IDENTIFIES AND DESCRIBES BASIC CASE-BASED OPERATIONS, AN ADVERSARIAL, CASE-BASED REASONING PROCESS, A SCHEMATIC STRUCTURE FOR CASE-BASED ARGUMENTS, THE KINDS OF COUNTER- EXAMPLES THAT ARISE AND THE KNOWLEDGE SOURCES NECESSARY TO SUPPORT ADVERSAR IAL, CASE-BASED REASONING. THE ''HYPO'' PROGRAM EMBODIES THE METHODOLOGY. IT COMPRISES: 1) A STRUC- TURED CASE KNOWLEDGE BASE ("CKB") OF ACTUAL LEGAL CASES; 2) AN INDEXING SCHEME ("DIMENSIONS") FOR RETRIEVAL OF RELEVANT CASES FROM THE CKB; 3) METHODS FOR ANALYZING PROBLEM SITUATIONS AND RETRIEVING RELEVANT CASES; 4) METHODS FOR INTERPRETING AND ASSESSING THE RELEVANCY OF PAST CASES BY "POSITIONING" THE PROBLEM SITUATION WITH RESPECT TO RELEVANT EXISTING CASES IN THE CKB AS SEEN FROM THE VIEWPOINT OF THE PROBLEM AT HAND AND FINDING THE MOST-ON-POINT CASES; 5) METHODS FOR COMPARING/CONSTRASTING CASES (E.G., CITING, DISTINGUISHING, FINDING COUNTER-EXAMPLES); 6) METHODS FOR POSING HYPOTHETICALS THAT TEST THE SENSITIVITY OF THE PROBLEM SITUATION TO CHANGES PARTICULARLY WITH REGARD TO POTENTIALLY ADVERSE EFFECTS OF NEW DAMAGING FACTS COMING TO LIGHT AND EXISTING FAVORABLE ONES BEING DISCREDITED; 7) METHODS FOR GENERATING "3-PLY" ARGUMENT OUTLINES TO PLAY OUT REALISTIC L