System and methods for a virtual assistant to manage and use context in a natural language dialog

摘要

A dialog with a conversational virtual assistant includes a sequence of user queries and systems responses. Queries are received and interpreted by a natural language understanding system. Dialog context information gathered from user queries and system responses is stored in a layered context data structure. Incomplete queries, which do not have sufficient information to result in an actionable interpretation, become actionable with use of context data. The system recognizes the need to access context data, and retrieves from context layers information required to transform the query into an executable one. The system may then act on the query and provide an appropriate response to the user. Context data buffers forget information, perhaps selectively, with the passage of time, and after a sufficient number and type of intervening queries.