The utterances of human languages have syntactic structure -- phrases being built from subphrases -- and their meanings have structure as well -- predicates applying to arguments, for instance. In fact, core cases of syntactic and semantic structure are so closely related as to suggest a direct correspondence between them. The syntax-semantics interface, that is, the formal architecture defining the relation between syntactic structure and semantic representation, ought to manifest this correspondence. This research advances the understanding of the syntax-semantics interface by using the formal concept of synchronization to characterize the relationship between syntactic and semantic grammars. The grammar synchronization method forms the basis for a model that, when properly calibrated, may simultaneously offer theoretical simplicity, computational plausibility, and the ability to capture the intricacies of the syntax-semantics interface for human language. The research will permit formal comparison of current linguistic theories of the syntax-semantics interface, bringing a dispersed area of research in linguistics and computer science into sharper focus.
By constructing and comparing grammar fragments that handle a wide range of linguistic constructions, the investigators will study the trade-off between computational efficiency and linguistic sufficiency inherent in a range of choices of formal structures for syntactic and semantic grammars and their synchronization. The end result will be a clearer picture of the computational implications of the relationship between the structure and the meaning of human languages and a method of expressing that relationship that permits efficient computation. As such, it serves as a step towards successful engineering of systems that can perform tasks such as interpreting sentences of English or other languages.
