Conversations abound with uncertainties of various kinds.
Treating conversation as inference and decision making under uncertainty, we propose a task independent, multimodal architecture for supporting robust continuous spoken dialog called Quartet . We introduce four interdependent levels of analysis, and describe representations, inference procedures, and decision strategies for managing uncertainties within and between the levels. Presenter , a prototype system for navigating Microsoft PowerPoint presentations, and the Bayesian Receptionist , a prototype system for dealing with tasks typically handled by front desk receptionists at the Microsoft corporate campus. Click here to access postscript or compressed postscript . Bayesian user modeling, common ground, joint activity, conversational systems, dialog systems, computational linguistics.