XPrag.de member Judith Degen from project “ProComPrag” is invited speaker at the workshop “Bridging Logical and Probabilistic Approaches to Language and Cognition” at ESSLLI 2015. The workshop will take place 3-7 August 2015, in Barcelona, Spain. Judith will talk on August, 7th at 11 a.m. on “Wonky Worlds: Modeling Prior Beliefs and Common Ground in Pragmatic Inference”.
Abstract: World knowledge enters into pragmatic utterance interpretation in complex ways and may be defeasible in light of speakers’ utterances. While effects of world knowledge on syntactic and semantic processing are well-established, there is to date a surprising lack of systematic investigation into the role of world knowledge in pragmatics. Here, we show that a state-of-the-art Bayesian model of pragmatic interpretation within the Rational Speech Act framework greatly overestimates the influence of world knowledge on the interpretation of utterances like Some of the marbles sank. We extend the model to capture the idea that listeners have uncertainty about the background knowledge the speaker is bringing to the utterance situation – and in effect., about the beliefs assumed to be in common ground. This extension greatly improves model predictions of listeners’ interpretation and also makes good qualitative predictions about listeners’ judgments of how ‘normal’ the world is in light of a speaker’s statement. We discuss alternatives to assuming malleable prior beliefs, including assuming that the speaker is uncooperative and that the speaker could have remained silent, and show for both that they are not the source of the compressed effect of world knowledge on utterance interpretation. We argue that this case study is an excellent demonstration of how combining behavioral experimentation and probabilistic computational modeling allows for gaining otherwise inaccessible insights into the interplay between language and cognition.