Completions, Coordination, and Alignment in Dialogue

Collaborative completions are among the strongest evidence that dialogue requires coordination even at the sub-sentential level; the study of sentence completions may thus shed light on a number of central issues both at the `macro’ level of dialogue management and at the `micro’ level of the semantic interpretation of utterances. We propose a treatment of collaborative completions in PTT, a theory of interpretation in dialogue that provides some of the necessary ingredients for a formal account of completions at the ‘micro’ level, such a theory of incremental utterance interpretation and an account of grounding. We argue that an account of semantic interpretation in completions can be provided through relatively straightforward generalizations of existing theories of syntax such as Lexical Tree Adjoining Grammar (LTAG) and of semantics such as (Compositional) DRT and Situation Semantics. At the macro level, we provide an intentional account of completions, as well as a preliminary account within Pickering and Garrod’s alignment theory.