1. A method for storing a document in a file system, comprising the steps of: determining a term weight for terms appearing in said document, wherein a given term weight is based on a frequency of occurrence of said corresponding term in a reference corpus: and storing said document in said file system with an indication of said term weights, wherein said given term weight is obtained by dividing a fractional frequency of said term in said document by a fractional frequency of said term in said reference corpus, wherein said fractional frequency of said term in said document is the number of occurrences of the term in the document divided by the total number of terms in the document and wherein said fractional frequency of said term in said reference corpus is the number of occurrences of the term in the reference corsus divided by the total number of words in the reference corpus.