Argument comprehension and retrieval for editorial text

Abstract

OpEd is a prototype editorial comprehension and question-answering system in the domain of politico-economic protection. Editorial comprehension in OpEd involves the application of: domain-specific knowledge, abstract knowledge of argumentation, and strategies for mapping input editorial text into conceptual structures. OpEd's model of domain-specific knowledge includes four major elements: authority triangles and social acts, to represent explicitly all the information associated with conflicts in international trade, including beliefs, goals, and conflict-resolution methods: goals and plans, to represent political and economic actions in terms of desired economic states; a trade graph, to represent causal relationships among the economic quantities associated with products and consumers; and reasoning scripts, to represent common chains of cause-effect relationships in editorials. OpEd's central, organizing constructs of argument knowledge are termed argument units (AUs). AUs consist of configurations of support and attack relationships among beliefs, where the content of each belief refers to goal/plan situations. The knowledge of argumentation encoded by AUs is highly abstract and independent of any particular domain. As a result, argument comprehension in OpEd requires instantiating AUs with the aid of politico-economic knowledge. Associated with each knowledge construct in OpEd are one or more processing strategies. These strategies are invoked to recognize knowledge constructs that are not explicitly stated in the text, but which must be inferred to understand the argument, planning and causal structure of the text. The result of processing strategies is the construction of an argument graph, organized in terms of beliefs, belief relationships, and AUs. Question answering in OpEd requires retrieving appropriate beliefs, belief relationships, or AUs from the editorial's argument graph. Intial entry to the argument graph is provided by indexing structures associated with argument participants, plans and goals. To answer belief-related questions, OpEd analyses the contents of each question into one of six conceptual question categories. Each conceptual question category leads to the selection of a specific search and retrieval strategy.