24. The computer program product of claim 13 , wherein the features comprise one or more of the following features: length of the essay in total number of words; percent of grammar errors with regard to total number of words; percent of usage errors with regard to total number of words; percent of mechanics errors with regard to total number of words; percent of style feedback comments with regard to total number of words; optimal number of discourse elements, wherein discourse elements are selected from the group consisting of background sentences, thesis sentences, main idea sentences, supporting idea sentences and conclusion sentences; average word length of discourse elements; score category to which the essay text is most similar with regard to vocabulary usage; similarity of the essay vocabulary to the vocabulary used in essays scored in the highest score category; ratio of number of words types to tokens in the essay; vocabulary level; and average word length.
13. A computer program product for automatically grading an essay, the essay being a response to a test prompt, the computer program product comprising a non-transitory computer readable storage medium having computer executable instructions thereon for causing a computer system to execute steps comprising: deriving a set of predetermined features from the essay, wherein the predetermined features comprise one or more features that are independent from the test prompt; evaluating the feature set with a scoring equation; generating a raw score for the essay from the scoring equation; and processing the raw score for the essay, wherein on an adaptive cutoff algorithm is utilized to assign the raw score to a score category, the computer executable instructions causing the computer system to execute steps according to the adaptive cutoff algorithm, comprising: collecting raw scored essays across all score categories, wherein the raw scored essays are graded by the automated deriving, evaluating, and generating steps and by human graders following scoring rubrics; determining an appropriate cutoff value set by maximizing an overall exact agreement between the automated grades and the human grades and a minimum lowest exact agreement between the automated grades and the human grades in a score category; and comparing the raw score generated by the deriving, evaluating, and generating steps to the selected cutoff set to obtain a score category for the essay.