THE INTERACTION OF REFERENTIAL AMBIGUITY AND ARGUMENT STRUCTURE IN THE PARSING OF PREPOSITIONAL PHRASES

This research addresses the question of whether the initial interpreta tion of structurally ambiguous sentences (such as He dropped the book on the chair) is made purely on the basis of syntactic principles or w hether semantic processes also exert an influence. Two factors, refere ntial ambiguity (e.g., whether there is more than one referent for the book), and verb argument structure (e.g., whether the verb takes on t he chair as an optional or obligatory argument) were manipulated in tw o experiments using a subject-paced moving-window technique. These exp eriments found that the need to resolve an ambiguous noun phrase refer ent interacted with the obligatory/optional nature of verb arguments. Discourse information affected initial syntactic assignment of the pre positional phrase, but only for verbs taking optional goal arguments. For verbs taking obligatory goal arguments, the attachment decision wa s independent of whether the noun phrase was referentially ambiguous. A third experiment found that prepositional phrases are not initially interpreted as modifiers if a disambiguating adjective immediately pre cedes the noun, clearly implicating referential ambiguity as the mecha nism affecting the interpretation of the prepositional phrase. These r esults support a limited influence of discourse semantics on the parsi ng of prepositional phrases and are inconsistent with models that prop ose no influence of semantics on syntax and models that propose comple te interaction. (C) 1994 Academic Press, Inc.