1. A method for use with a collection of documents, the method comprising: generating categories representing fields of expertise derived from the collection of documents, including generating a taxonomy from the collection of documents, wherein said generating of categories includes generation of a feature space from text of the collection of documents and comparison of the collection of documents using a measure of distance in the feature space; converting each of the documents in the collection of documents into a numeric vector corresponding to word, feature, and information content of each of the collection of documents; extracting structured fields from the collection of documents, the extraction being performed by a computer processor; classifying the collection of documents based on the extracted structured fields; refining the taxonomy by applying user domain knowledge to create the classifications of documents; further refining the taxonomy by merging, deleting and adding classes to the taxonomy; constructing a contingency table having a first axis defined by the extracted structured fields and a second axis defined by the categories; and using the contingency table to identify a set of experts having a related expertise; and determining a statistical relationship between the identified set of experts and one of the extracted structured fields in the table.