Systems and methods are provided for automatically scoring essay responses to a prompt using a scoring model. A relevant word corpus and an irrelevant word corpus are accessed. A scoring model is generated by, for each of a plurality of words in the relevant word corpus, determining a topic signature score based on a number of appearances of that word in the relevant word corpus and a number of appearances of that word in the irrelevant word corpus. For each of a plurality of words in an essay response, a topic signature score is determined for that word. A score for the essay response is determined based on the identified topic signature scores.