Semantics and Quantification in Natural Language Question Answering

This paper is concerned with the semantic interpretation of natural English sentences by a computerized question-answering system, and specifically with tne problems of interpreting and using quantification in such systems. Those issues are presented and discussed from the perspective of four different natural language understanding systems with which the author has been involved. The presentation includes the process of semantic interpretation, the nature and organization of semantic interpretation rules, a notation for representing semantic interpretations (the meaning representation language), the semantics of that notation, and the generation and scoping of quantifiers. Also discussed are a variety of loose ends, open questions, and directions for future research. Particular attention is given to the interaction of syntactic, semantic (and pragmatic) information.