Robust Neural Automated Essay Scoring Using Item Response Theory

Automated essay scoring (AES) is the task of automatically assigning scores to essays as an alternative to human grading. Conventional AES methods typically rely on manually tuned features, which are laborious to effectively develop. To obviate the need for feature engineering, many deep neural network (DNN)-based AES models have been proposed and have achieved state-of-the-art accuracy. DNN-AES models require training on a large dataset of graded essays. However, assigned grades in such datasets are known to be strongly biased due to effects of rater bias when grading is conducted by assigning a few raters in a rater set to each essay. Performance of DNN models rapidly drops when such biased data are used for model training. In the fields of educational and psychological measurement, item response theory (IRT) models that can estimate essay scores while considering effects of rater characteristics have recently been proposed. This study therefore proposes a new DNN-AES framework that integrates IRT models to deal with rater bias within training data. To our knowledge, this is a first attempt at addressing rating bias effects in training data, which is a crucial but overlooked problem.