37. A method for providing a cooperative conversational voice user interface, comprising: receiving an utterance at a voice input device during a current conversation with a user; accumulating short-term shared knowledge about the current conversation, wherein the short-term shared knowledge includes knowledge about the utterance received during the current conversation; accumulating long-term shared knowledge about the user, wherein the long-term shared knowledge includes knowledge about one or more past conversations with the user; determining an intended meaning for the utterance, wherein determining the intended meaning for the utterance includes: identifying, at a conversational speech engine, a context associated with the utterance from the short-term shared knowledge and the long-term shared knowledge; inferring additional information about the utterance from the short-term shared knowledge and the long-term shared knowledge in response to determining that the utterance contains insufficient information to complete a request in the identified context; and establishing the intended meaning within the identified context based on the additional information inferred about the utterance; and generating a response to the utterance based on the intended meaning established within the identified context.
37. A method for providing a cooperative conversational voice user interface, comprising: receiving an utterance at a voice input device during a current conversation with a user; accumulating short-term shared knowledge about the current conversation, wherein the short-term shared knowledge includes knowledge about the utterance received during the current conversation; accumulating long-term shared knowledge about the user, wherein the long-term shared knowledge includes knowledge about one or more past conversations with the user; determining an intended meaning for the utterance, wherein determining the intended meaning for the utterance includes: identifying, at a conversational speech engine, a context associated with the utterance from the short-term shared knowledge and the long-term shared knowledge; inferring additional information about the utterance from the short-term shared knowledge and the long-term shared knowledge in response to determining that the utterance contains insufficient information to complete a request in the identified context; and establishing the intended meaning within the identified context based on the additional information inferred about the utterance; and generating a response to the utterance based on the intended meaning established within the identified context. 38. The method of claim 37 , wherein the established intended meaning comprises an implicit hypothesis having a corresponding degree of certainty about an intent that the user had in speaking the utterance.