Probabilities and logic in implicature computation: Two puzzles with embedded disjunction

Sentences are standardly assumed to trigger scalar and ignorance implicatures because there are alternative utterances the speaker could have said. The central question in modeling these inferences is thus: what counts as an alternative utterance for a given sentence in a given context? In this paper, I will present two families of novel empirical observations related to inference and deviance patterns of embedded disjunction, based on which I will argue that (i) probabilistic informativeness plays a role in selecting the set of alternatives; and (ii) the role of prior world knowledge in evaluating probabilistic informativeness of alternatives is limited. EARLY ACCESS