Talk: Defining Relevance for Imperatives in Discourse

October 19, 2012
1st International Pragmatics Conference of the Americas, Charlotte NC

Abstract
Work on the semantics of discourse (Roberts 2004; Roberts et al. 2009; Simons et al. 2011) has defined relevance for an utterance, i.e. when content makes a fruitful contribution to the discourse topic, or Question Under Discussion (QUD). Simons et al. (2011) defines relevance for assertions and questions (1–2), but not for commands.

(1)  An assertion is relevant if it contextually entails a partial or complete answer to the QUD.

(2)  A question is relevant if it has an answer which contextually entails a partial or complete answer to the QUD.

I extend relevance to commands, yielding a unified definition of relevance that generalizes across clause types. Following Starr (2010), I represent imperatives semantically as preferences which rank one proposition over another; the effect in discourse is a command. I propose the following definition of relevance for commands, modeled after those in Simons et al. (2011).

(3) A command is relevant if what it prefers contextually entails a partial or complete answer to the QUD.

Following Murray (2010), I divide the semantic contribution of sentences into their propositional content and an illocutionary relation, which takes the discourse context and a proposition, and returns an updated, structured context. The illocutionary relation of declaratives performs set intersection; that of questions partitions the context. I propose that the illocutionary relation of imperatives imposes a preference. Splitting meaning into two parts allows relevance to be generalized across clause types. All three definitions (1–3) are in terms of an illocutionary relation and propositional content, and naturally collapse into a unified definition.

(4) Generalized Relevance
An utterance is relevant if the propositional argument of its illocutionary relation contextually entails a partial or complete answer to the QUD.

Generalizing relevance not only makes the concept more complete, but crucially ties it to illocutionary relations.