Now that you mention it: Awareness dynamics in discourse and decisions

Abstract. We model unawareness of possibilities in decision making and pragmatic reasoning. A background model is filtered through a state of limited awareness to provide the epistemic state of an agent who is not attending to all possibilities. We extend the standard notion of awareness with assumptions (implicit beliefs about propositions the agent is unaware of) and define a dynamic update for 'becoming aware. ' We give a propositional model and a decision-theoretic model, and show how pragmatic relevance reasoning can be described in the latter. An utterance can be relevant even if semantically uninformative, if it brings relevant alternatives to awareness. This gives an explanation for the use of possibility modals and questions as hedged suggestions, bringing possibilities to awareness but only implicating their degree of desirability or probability. Our aim in this paper is to introduce the notion of unawareness into formal pragmatics and to show how this helps extend existing decision-theoretic approaches. It is a rather commonplace observation that when using language on an everyday basis, we do not attend to all conceivable possibilities all of the time. Quite sensibly, we do not devote attention and consideration to far-fetched and bizarre contingencies that are of little practical effect. Less sensibly, but inevitably, we also occasionally fail to recognise genuinely relevant possibilities: we forget, we overlook, we miss connections and fail to draw conclusions. Recent research in rational choice theory converged on the realization that the epistemic attitudes we have to such overlooked possibilities are not well represented by either belief (as standardly understood) or by uncertainty. To cope with unawareness, we therefore need richer representations of an agent's cognitive state to encode not only the agent's beliefs but also which possibilities she conceives of and which she is unaware of. These insights are relevant to formal semantics and pragmatics. Palpably, awareness of possibilities can change in the course of a conversation. More crucially even, if unawareness is frequent and object to change in conversation, then The authors are listed in alphabetical order. We would like to thank: Sven Lauer and two anonymous referees for their attention to the manuscript; Robert van Rooij and Remko Scha for discussion of the notions; Anton Benz for the invitation to present these ideas at the zas, Berlin; and audiences in Amsterdam and Berlin for the valuable feedback we have received

Knowing whether A or B

Abstract. The paper examines the logic and semantics of knowledge attributions of the form “s knows whether A or B”. We analyze these constructions in an epistemic logic with alternative questions, and propose an account of the context-sensitivity of the corresponding sentences and of their presuppositions

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Analysing the complexity of games on graph

Some New Observations on ‘Because (of)’

Solstad T. Some New Observations on ‘Because (of)’. In: Aloni M, Bastiaanse H, de Jager T, Schulz K, eds. Logic, Language and Meaning. Lecture Notes in Computer Science. Vol 6042. Berlin ; Heidelberg: Springer ; 2010: 436-445