5. The method of claim 1 , where determining that the first word is the keyword for the particular category further includes: determining a score for the first word; and determining that the first word is the keyword for the particular category further based on determining that the score satisfies a score threshold.
5. The method of claim 1 , where determining that the first word is the keyword for the particular category further includes: determining a score for the first word; and determining that the first word is the keyword for the particular category further based on determining that the score satisfies a score threshold. 6. The method of claim 5 , where the score for the first word is based on a third value associated with a third frequency that the first word appears in the collection of documents.