Proceedings of the Annual Meeting of the Cognitive Science Society

For almost two decades, the poor performance observed withthe so-called Director task has been interpreted as evidence oflimited use of Theory of Mind in communication. Here wepropose a probabilistic model of common ground in referentialcommunication that derives three inferences from an utterance:what the speaker is talking about in a visual context, what sheknows about the context, and what referential expressions sheprefers. We tested our model by comparing its inferences withthose made by human participants and found that it closelymirrors their judgments, whereas an alternative modelcompromising the hearer’s expectations of cooperativenessand efficiency reveals a worse fit to the human data. Ratherthan assuming that common ground is fixed in a givenexchange and may or may not constrain reference resolution,we show how common ground can be inferred as part of theprocess of reference assignment.