Avoiding attachment ambiguities: The role of constituent ordering

Three experiments investigated whether speakers use constituent ordering as a mechanism for avoiding ambiguities. In utterances like "Jane showed the letter to Mary to her mother," alternate orders would avoid the temporary PP-attachment ambiguity ("Jane showed her mother the letter to Mary," or "Jane showed to her mother the letter to Mary"). A preference judgment experiment confirmed that comprehenders prefer the latter orders for dative utterances when the former order would have contained an ambiguity. Nevertheless, speakers in two on-line production experiments showed no evidence of an ambiguity avoidance strategy. In fact, they were slightly more likely to use the former order when it was ambiguous than when it was not. Speakers' failure to disambiguate with ordering cannot be explained by the use of other ambiguity mechanisms, like prosody. A prosodic analysis of the responses in Experiment 3 showed that while speakers generally produced prosodic patterns that were consistent with the syntactic structure, these patterns would not strongly disambiguate the PP-attachment ambiguity. We suggest that speakers do not consistently disambiguate local PP-attachment ambiguities of this type, and in particular do not use constituent ordering for this purpose. Instead, constituent ordering is driven by factors like syntactic weight and lexical bias, which may be internal to the production system. (C) 2004 Elsevier Inc. All rights reserved.