1. A method of automatically creating a dictionary for clustering text documents comprising: inputting a maximum dictionary size; determining a frequency of each word in each of said documents; 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 creating said dictionary, determining a frequency of phrases in each of said documents that contain only words in said dictionary; 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.