Proceedings of the Annual Meeting of the Cognitive Science Society

Successful communication regularly requires listeners to makepragmatic inferences — enrichments beyond the literal mean-ing of a speaker’s utterance. For example, when interpretinga sentence such as “Alice ate some of the cookies,” listenersroutinely infer that Alice did not eat all of them. A Griceanaccount of this phenomenon assumes the presence of alterna-tives (like “all of the cookies”) with varying degrees of infor-mativity, but it remains an open question precisely what thesealternatives are. To address this question, we collect empiricalmeasurements of speaker and listener judgments about vary-ing sets of alternatives across a range of scales and use these asinputs to a computational model of pragmatic inference. Thisapproach allows us to test hypotheses about how well differ-ent sets of alternatives predict pragmatic judgments by peo-ple. Our findings suggest that comprehenders likely considera broader set of alternatives beyond those logically entailed bythe initial message.