1. A computer-implemented method comprising: applying an essay to a plurality of trait models with a computer; identifying a plurality of features associated with a vocabulary usage trait of the plurality of trait models with the computer; identifying multiple features associated with a discourse trait of the plurality of trait models with the computer, wherein the identifying multiple features comprises identifying a thesis, a main idea, a supporting idea, and a conclusion; automatically determining a plurality of trait scores based on the plurality of trait models with the computer, each trait score generated from a respective trait model; and assigning a score to the essay with the computer, based on the plurality of trait scores.