Text Readability Assessment for Second Language Learners
Table 9: Results of self-training
['Type', 'ACC', 'PCC']
We have experimented with a grid search on K’s and the number of iterations, and found out that whatever the choice of the parameters is, the model performance degrades with self-training when the unlabeled instances are added blindly to all levels of the L2 dataset. Taking into account the mismatch in the difficulty levels between the native and L2 texts, we adapted the algorithm to add the unlabeled data only to the lower three levels of the L2 dataset. It seems reasonable to compare the results of this approach to those obtained with a model that is trained directly on the L2 data.