6. A method of automatically creating a dictionary for clustering text documents comprising: inputting a maximum dictionary size; performing a first pass for each of said documents comprising: determining a frequency of each word in each of said documents; and creating a dictionary of most frequently occurring words in said documents as limited by said maximum dictionary size, such that said dictionary contains less than all words in said documents; after performing said first pass, performing a second pass for each of said documents comprising: determining a frequency of phrases in each of said documents that contain only words in said dictionary; and adding most frequently occurring phrases to said dictionary; and outputting said most frequently occurring words and said most frequently occurring phrases as said dictionary, wherein said dictionary size limits the number of words and phrases maintained in said dictionary.
6. A method of automatically creating a dictionary for clustering text documents comprising: inputting a maximum dictionary size; performing a first pass for each of said documents comprising: determining a frequency of each word in each of said documents; and creating a dictionary of most frequently occurring words in said documents as limited by said maximum dictionary size, such that said dictionary contains less than all words in said documents; after performing said first pass, performing a second pass for each of said documents comprising: determining a frequency of phrases in each of said documents that contain only words in said dictionary; and adding most frequently occurring phrases to said dictionary; and outputting said most frequently occurring words and said most frequently occurring phrases as said dictionary, wherein said dictionary size limits the number of words and phrases maintained in said dictionary. 7. The method in claim 6 , wherein said determining a frequency of each word comprises: removing punctuation and case from said documents; removing stop words from said document; replacing words in said documents with synonyms; removing duplicate words from said documents; adding remaining words to said dictionary as limited by said maximum dictionary size; determining said frequency of each word remaining in said dictionary; and removing words below a frequency level from said dictionary.