All together now . . . This time with meaning : A hierarchical lexicon for semantic coordination

Classically, semantic theories have assumed that words are endowed with universal, immutable meanings. This assumption is not tenable when modeling natural language dialogue; far from treating word meanings as fixed entities, linguistic agents are constantly coordinating useful semantic conventions. They disambiguate polysemous words, construct ad hoc interpretations particular to their communicatory goals, and ultimately learn new ways to use old words based on these collaborations. This thesis proposes a lexical model for dialogue semantics that supports semantic coordination. The model that is proposed employs a hierarchical lexicon to distinguish between the different kinds of shared semantic information. It is used to build a theory of semantic coordination that drives lexicosemantic learning and tends to introduce polysemy in the lexicon. The lexical model and theory of semantic coordination are formalized using Type Theory with Records, which uses feature structure-like objects to store semantic information. Finally, the thesis presents some empirical work: A corpus study on contrastive focus reduplication—one strategy for semantic coordination—confirms predictions made by the pragmatic and semantic theory presented earlier, and a signaling games simulation supports the connection between semantic coordination and polysemy that is predicted by the hierarchical lexical model.