17. The method of claim 16 , further comprising: receiving a value for a customized ranking parameter from a user by the computer processing system; and calculating the relevance score as a function of the first frequency, the second frequency, and the customized ranking parameter.
17. The method of claim 16 , further comprising: receiving a value for a customized ranking parameter from a user by the computer processing system; and calculating the relevance score as a function of the first frequency, the second frequency, and the customized ranking parameter. 18. The method of claim 17 , further comprising: receiving, from the user interface by the computer processing system, user's preference for different types of contents in the one or more documents to be returned by the computer processing system, wherein the preferences for the different types of contents comprise at least one of “general”, “specific”, “detailed”, “brief”, “query-specific”, or “conceptual”.