1. In a computing environment, a method comprising: extracting, by a computer, topics from a 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 page; and computing, by the computer, 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.