A question-answering system for high school algebra word problems

The aim of the research reported here was to discover methods for building computer programs which can understand and communicate with people in a non-trivial subset of English. A computer program understands a subset of English if it accepts input sentences which are members of this subset, and answers questions based on information contained in the input. We describe in this paper a semantic theory of discourse, and utilize a first approximation to the analytical portion of this theory in the STUDENT question-answering system, a program which understands a subset of English in the sense defined above.