26. A method of re-ranking a list of document obtained from a search wherein a ranking of a document in the list of documents is determined by a relevance of the document to a search text, wherein the list of documents has been classified and appears in an inverted list, said inverted list comprising for each topic category of a classification system a weight associated with a particular document of the list of documents, the weight representing a degree to which the particular document relates to said each topic category, the weights obtained automatically from a computer program, the method having a scalable time complexity of O(N x ) where 0<=X<=1.0 for a universe of text on the world wide web and comprising: creating a fingerprint for a first piece of text, the fingerprint comprising a list of weights associated with particular topic categories in the classification system, each of the weights in the fingerprint for said first piece of text representing a degree to which the first piece of text relates to the particular topic category that the weight in the fingerprint for said first piece of text is associated with, the weights in the fingerprint for said first piece of text obtained automatically from a computer program, a computer processor searching the list of documents by comparing the fingerprint for the first piece of text with the fingerprint for each document in the list of documents, and a computer processor re-ranking the list of documents based on a degree to which a fingerprint of a document in the list has a mathematical overlap with the fingerprint of the first piece of text, the method configured to re-rank the list of documents based on relevance to the search text whether the list of documents includes text written in one language or in more than one language.
30. The method of claim 26 , wherein a selected number of weights is between 1 and 75 and the classification system is the Dewey Decimal System.