1. A method for reducing dimensions of a document vector used to determine the similarity of a first document to a plurality of other documents in a computer, the method comprising: receiving a document that is input to the computer for determining the similarity of the document to the plurality of other documents; preprocessing the document to generate a document vector; reducing a number of dimensions in the document vector; comparing the document vector to at least one document vector for the plurality of documents to determine a similarity of the document to the plurality of other documents; and displaying a measure of similarity of the document to the other documents to a human observer.