15. The at least one computer storage medium of claim 14 wherein the extracting is from at least one of a group comprising a title of the web page, anchor text of the web page, a uniform resource locator (“URL”) referencing the web page, tags assigned to the web page, a query associated with the web page, and a body of the web page.
14. At least one computer storage medium having computer-executable instructions that, when executed by a computer, cause the computer to perform a method comprising: extracting topics from each web page of a set of web pages that correspond to a query, wherein the topics are noun phrases that represent subjects of the web pages; computing a relevance score for each extracted topic, wherein each relevance score is based on a predicted match level from a group of match levels comprising a first match level that indicates an exact match between the each extracted topic and the query, a second match level that indicates a same meaning between the each extracted topic and the query, a third match level that indicates that the each extracted topic is relevant to the query, a fourth match level that indicates that the each extracted topic is irrelevant to the query, and a fifth match level that indicates that the each extracted topic does not match the query, and wherein the predicted match level is based on a conditional probability model P(L|Q→T) where L denotes a level, and where Q→T denotes an event that comprises generating topic T from query Q; and ranking the web pages relative to one another based on the computed relevance scores.