Text Readability Assessment for Second Language Learners
Table 5: Confusion matrix of the classification model on the language testing data
['Levels', '1', '2', '3', '4', '5']
In the case of the multi-class classification model, the accuracy dropped greatly when the model is applied to the L2 dataset, while the correlation remained relatively high. This is because, on average, the Cambridge Exams texts are more difficult than the WeeBit corpus ones which are generally targeted at children of young ages. Thus, the mismatch between the targeted levels has led to poor generalization of the classification model.