1. A computer-implemented method of automatically generating a coherence score for a text using a scoring model, comprising: identifying a lexical chain within a text to be scored with a processing system, wherein the lexical chain comprises a set of words spaced within the text; identifying a discourse element within the text with the processing system based on lookup operations with a computer database of discourse elements, wherein the discourse element comprises a word within the text; determining a coherence metric with the processing system based on a relationship between the lexical chain and the discourse element; generating a coherence score using the processing system by applying a scoring model to the coherence metric, wherein the scoring model comprises multiple weighted features whose feature weights are determined by training the scoring model relative to a plurality of training texts.