10. The method of claim 9 , wherein the comparing comprises: generating argument partitioned text from the essay, said argument partitioned text comprising a structure identifier describing an aspect of the argument structure of the sentence; for each of a plurality of score categories, each score category having a plurality of score category essays, creating a word weight vector for each of a set of argument words in the plurality of score categories essays; creating a word weight vector for each of a set of argument words in the essay; computing for each of the set of argument words in the essay, a cosine correlation between the argument word weight vector for a particular argument word in the essay and the word weight vector for the same argument word in the plurality of score category essays; and assigning to each of the set of argument words in the essay the score class having the highest cosine correlation.
9. The method of claim 8 , wherein the content features are derived by comparing word usage of the essay to a batch of essays scored over the range of score categories.