Question Answering Using Syntax-Based Concept Nodes

This paper presents a syntax-based formalism for representing atomic propositions extracted from textual documents. A method is described for constructing a network of concept nodes for indexing such logical forms based on the discourse entities they contain. The decomposition of meaningful questions into Boolean combinations of question patterns using the same formalism is presented, in which free variables represent the desired answers. A method is described for using this formalism for robust question answering using the concept network and WordNet synonym, hypernym, and antonym relationships. Finally, the encouraging performance of an implementation of this formalism against the factoid questions from the 2005 Text Retrieval Conference, which operated upon the AQUAINT document corpus, is discussed