Informative Presupposition & Accommodation

Abstract

Presuppositions are the parts of meanings of utterances which are backgrounded and strongly committed to by the speaker. They are carried by a diverse range of lexical items called presupposition triggers, which include determiners, particles, open class verbs, and syntactic constructions. For example, the sentence "Lee read War and Peace again" asserts that Lee read War and Peace and presupposes that she has done so previously via the trigger 'again.' Most triggers occur in contexts where their presuppositions are supported (i.e. already entailed) by a local context; however some can also occur in contexts that lack local support, in which case their presuppositions are informative. Informative use of presupposition is typically modeled via an accommodation mechanism (Lewis, 1979) that pre-updates a context prior to utterance interpretation to go along with the presuppositions of a sentence. Understanding when triggers can communicate novel information using accommodation---which I refer to as the "Novelty Problem" for presupposition triggers---is the main goal of this dissertation.

The dissertation is arranged into five chapters. Chapter 1 provides a background on presupposition and accommodation, and introduces the notion of Contextual Felicity Constraints, or CFCs (Tonhauser et al., 2013). If a trigger is infelicitous in cases where its presuppositions are not entailed, it is said to be subject to a strong CFC. Chapter 2 measures the CFCs for thirteen English presupposition triggers in two online comprehension studies, making it the largest cross-trigger comparison of CFCs reported in the literature to-date. A ranking of triggers is proposed, from weak-CFC triggers to strong-CFC triggers. Chapter 3 presents a theoretical solution to the novelty problem, which views CFCs as the result of an information-structural discourse clash. The proposal, which I refer to as the Maximalty/Accommodation Clash (or MAC), treats CFCs as arising not from accommodation failure, but from downstream semantic contradictions that result from successful accommodation. Chapter 4 develops this proposal within alternative pragmatic frameworks. Finally, Chapter 5 presents two studies that test the MAC experimentally. Taken together, the results lend support for the perspective that presupposition triggers impose constraints on the context in which they are uttered and that their contextual felicity is modulated by local information structure---the two key ingredients of the MAC approach