"The project concerns the semantics of modal expressions in language, and in particular modal verbs such as 'might', 'must' and 'can'. The hypothesis under investigation is the Probabilistic Construal of Modality, stating that modal verbs like the above should be given a semantic analysis in terms of (among other things) probability functions. This is a very active topic of research within philosophy and linguistic semantics, which is generating a large amount of literature. The project will improve on the state of the art in this literature in four respects. First, it will clarify the basic question, outlining explicitly the methodology for a systematic study of the PCM hypothesis. Second, it will undertake a systematic investigation of the compositional interactions of modals and other operators in language. Third, it will draw much needed conceptual connections between the semantics of modality and probabilistic models of belief. Finally, it will revisit important classical literature on the connection between probabilities of conditional statements and conditional probabilities."