1. A computer-implemented method for annotating an essay, comprising: identifying a sentence of an essay with a computer; identifying by the computer a feature associated with said sentence; determining by the computer a probability of said sentence being a discourse element by mapping said feature to a model, said model having been generated by a machine learning application trained based on at least one annotated essay; and annotating by the computer said essay based on said probability, wherein said discourse element is at least one of: a title, a background, a thesis statement, a main point, support and conclusion.