Modularity and Soft Constraints a Study of Conflict Resolution in Grammar

This thesis advocates a modular and parallel grammar architecture with declarative constraints on the syntactic, semantic, prosodic, and pragmatic structures which are derived in parallel while mutually constraining one another as proposed by Jackendoff (1997, 2002). The main claim of this thesis is that because of the many conflicting requirements among modules, the interfaces cannot employ crisp constraints. Instead, a soft-constraint satisfaction approach is required. We also argue that simply violable constraints are insufficient to account for certain linguistic phenomena; there is need for graded constraints that allow for degrees of violation. The dissertation first provides a review of different conceptions of gradience in linguistics followed by a review of the concept of modularity in cognitive science and linguistics. The problem of conflicting requirements in the field of Constraint Logic Programming (CLP) has led to various soft constraint satisfaction approaches. The dissertation then presents a generalized theory of soft constraint satisfaction (Bistarelli, 2001) from the CLP literature. The dissertation then presents a case study of graded constraints showing that such constraints exist at interfaces and that they can exhibit degrees of violation. Another case study shows that the modular parallel architecture allows for simpler modules and is able to capture generalizations better. We then conclude by showing how the generalized theory of soft-constraint satisfaction can be incorporated within grammar without disrupting the existing explanatory power of constraint-Acknowledgments I spent much of the last four years of my life alone at RL-14221, a windowless room on the 14th floor of Robarts Library, which I fondly call the Linguistics Super-fix because it is one of a few rooms that the Linguistics Department has on the 14th floor, the rest of it being on the sixth where all the fun is. But I did not or could not write this thesis alone by any means. If it weren't for the strong support of almost everyone I have interacted with while at UofT, none of this would have been possible. First and foremost, I'd like to thank my co-supervisors Elizabeth Cowper and Gerald Penn. Elizabeth was one of my first points of contact with formal linguistics even before I came to UofT (I studied her Government and Binding textbook in Iran). She was there when I started learning linguistics; she was there when I started tearing it apart and turning it upside down. She has always welcomed me with her pleasant smile (which you …