REPROLANG 2020 - Automatic Proficiency Scoring of Czech, English, German, Italian, and Spanish Learner Essays.

We report on our attempts to reproduce the work described in Vajjala and Rama (2018), 'Experiments with universal CEFR classification', as part of REPROLANG 2020: this involves featured-based and neural approaches to essay scoring in Czech, German and Italian. Our results are broadly in line with those from the original paper, with some differences due to the stochastic nature of machine learning and programming language used. We correct an error in the reported metrics, introduce new baselines, apply the experiments to English and Spanish corpora, and generate adversarial data to test classifier robustness. We conclude that feature-based approaches perform better than neural network classifiers for text datasets of this size, though neural network modifications do bring performance closer to the best feature-based models.