1. A web search system comprising: a memory; a processing unit coupled to the memory, the processing unit configured to execute computer-implemented components comprising: a search engine that receives search queries and identifies web pages relevant to the search queries; an inference component that infers web page information relevant to a current search query by generating one or more questions, initiating a communication session to communicate the one or more questions to a user, and receiving one or more user supplied answers from the user to the one or more questions via the communication session, the inference component further modifies a heuristic rule pertaining to a search domain classified by a topic hierarchy or a topic cluster based on knowledge learned from the inferred web page information associated with the one or more user supplied answers to generate a modified heuristic rule; and a query modification component that alters the current search query based at least on the inferred webpage information, the modified heuristic rule, and a navigated position in the topic hierarchy or the topic cluster.