An information-based theory of topics and grammatical relations
This dissertation proposes a formal semantic characterization of topichood and an account of the relationship between Topic and core Grammatical Relations. The theoretical framework employed is a form of HPSG (Pollard & Sag (1994)). The notion of Topic has been widely invoked in descriptions both of sentence structure and of intersentential discourse relations. Despite this a formal characterization of this notion is lacking in the literature. It is proposed here that Topics should be seen as predication targets at an underlying semantic level, and that the Topic-Comment relation is analogous to that between possible worlds (situations) and the propositional contents which they support. A Topic is interpreted as a point whose location has to be fixed in some conceptual space formed by the Comments, and this metaphor is extended to the overall Topic of a discourse sequence. Formally, it is suggested that Topics and Comments can be treated as the points and open sets respectively of a topological space. It is claimed that this captures well-known semantic restrictions on which NPs can be made Topics of a sentence. The proposed treatment is also extended to intersentential Topic relations. This account of Topics
Gregory, Howard Anthony Oliver
Linguistics
An information-based theory of topics and grammatical relations. This dissertation proposes a formal semantic characterization of topichood and an account of the relationship between Topic and core Grammatical Relations. The theoretical framework employed is a form of HPSG (Pollard & Sag (1994)). The notion of Topic has been widely invoked in descriptions both of sentence structure and of intersentential discourse relations. Despite this a formal characterization of this notion is lacking in the literature. It is proposed here that Topics should be seen as predication targets at an underlying semantic level, and that the Topic-Comment relation is analogous to that between possible worlds (situations) and the propositional contents which they support. A Topic is interpreted as a point whose location has to be fixed in some conceptual space formed by the Comments, and this metaphor is extended to the overall Topic of a discourse sequence. Formally, it is suggested that Topics and Comments can be treated as the points and open sets respectively of a topological space. It is claimed that this captures well-known semantic restrictions on which NPs can be made Topics of a sentence. The proposed treatment is also extended to intersentential Topic relations. This account of Topics
information based theory topic grammatical_relation proposes formal_semantic characterization account relationship topic core grammatical relations theoretical_framework employ form hpsg notion topic widely invoke description sentence_structure discourse relation despite formal characterization notion lack literature propose topics see predication target underlie semantic_level topic comment relation analogous possible_world situation propositional content support topic interpret point whose location fix conceptual space form metaphor extend overall topic discourse sequence formally suggest topics treat point open set respectively topological space claimed capture well_known semantic restriction nps make topics sentence propose treatment also extend topic relation account topics