14. The system of claim 13 wherein calculating the tf-idf value of each selected term further comprises: calculating an inverse document frequency (idf) value of the term in relation to the corpus of documents; calculating a term frequency (tf) value of the term; and determining the tf-idf value of the term based on the idf value of the term and the tf value of the term.
14. The system of claim 13 wherein calculating the tf-idf value of each selected term further comprises: calculating an inverse document frequency (idf) value of the term in relation to the corpus of documents; calculating a term frequency (tf) value of the term; and determining the tf-idf value of the term based on the idf value of the term and the tf value of the term. 16. The system of claim 14 wherein calculating the tf value of the term further comprises dividing a number of times the term appears in the text by a length of the text.