Handling Scope Ambiguities In English

This paper describes a program for handling "scope ambiguities" in individual English sentences. The program operates on initial logical translations, generated by a parser/translator, in which "unscoped elements" such as quantifiers, coordinators and negation are left in place to be extracted and positioned by the scoping program. The program produces the set of valid scoped readings, omitting logically redundant readings, and places the readings in an approximate order of preference using a set of domain-independent heuristics. The heuristics are based on information about the lexical type of each operator and on "structural relations" between pairs of operators. The need for such domain-independent heuristics is emphasized; in some cases they can be decisive and in general they will serve as a guide to the use of further heuristics based on domain-specific knowledge and on the context of discourse. The emphasis of this paper is on discussing several of the more problematic aspects of the scoping protocol which wcre encountered during the design of the scoping program.