Resolving attachment ambiguities with multiple constraints.

Different theories of syntactic ambiguity resolution argue for different sources of information determining initial parsing decisions (e.g., structurally defined parsing principles, lexically specific biases, or referential pragmatics). However, a "constraint-based" approach to syntactic ambiguity resolution proposes that both lexically specific biases and referential pragmatics are used in parallel by the comprehender. Analyses of text corpora, sentence fragment completions, and self-paced reading experiments were conducted to demonstrate that both local information (lexically specific biases) and contextual information (referential presupposition) contribute to the on-line resolution of prepositional phrase attachment ambiguities. There does not appear to be a role for purely structurally defined parsing principles (i.e., minimal attachment). Present and previous evidence is consistent with a developing framework in which multiple constraints (bottom-up and top-down) interact immediately to determine initial syntactic commitments.