Systems and methods for building a trait model for essay evaluation are provided. At least one evaluated essay is received. A plurality of features pertaining to one or more traits from the at least one evaluated essay are identified and extracted. The one or more traits comprise writing errors, discourse, or vocabulary usage. A plurality of vector files based upon the plurality of features are created. A trait model for essay evaluation based upon the plurality of vector files is built. The trait model is evaluated, where the evaluation includes mapping features of a new essay to the trait model by navigating a multi-branched decision tree. At each branch of the decision tree, a value associated with the features of the new essay is used to determine how to proceed through the trait model.