Making Use of Extensional Definitions of Principles and Cases

General principles are abstract rules intended to guide decision makers in making normative judgments in domains like law, politics, and ethics. It is difficult, however, if not impossible to define principles in an intensional manner so that they may be applied deductively. The problem is the gap between abstract, open-textured principles and concrete facts. On the other hand, when expert decision makers rationalize their conclusions in specific cases, they often link principles to the specific facts of the cases. In effect, these expert-defined associations between principles and facts provide extensional definitions of the principles. The experts operationalize the general principles by linking them to the facts. After analyzing a large set of professional ethics case opinions, we hypothesized that extensionally-defined principles, as well as cited past cases, could help in predicting the principles and cases that might be relevant in the analysis of new cases. To investigate this phenomenon computationally, we constructed SIROCCO, a system for retrieving principles and past cases. This paper presents empirical evidence that the operationalization information contained in extensionally-defined principles can indeed be leveraged to predict relevant principles and past cases. We show this through an ablation experiment comparing SIROCCO to a version of itself that does not employ operationalization information. Further, we show that SIROCCO’s extensionally-defined principles and case citations help it outperform information retrieval programs that do not employ such information.