Learning to Copy for Automatic Post-Editing
Table 6: Ablation study. “Interactive” denotes interactive representation learning (Section 3.1), “Predictor” denotes detecting correct words (Section 3.2), “CopyNet” denotes the CopyNet used in our approach (Section 2.2), and “Joint Training” denotes the combination of three loss functions (Section 3.3).
['ID', 'Module Interactive', 'Module Predictor', 'Module CopyNet', 'Module Joint Training', 'DEV16 TER↓', 'DEV16 BLEU↑', 'TEST16+17 TER↓', 'TEST16+17 BLEU↑']
It is clear that interactive representation learning plays a critical role since removing it impairs post-editing performance (line 3). As shown in line 4, the Predictor is also an essential part of our approach. CopyNet and joint training are also shown to be beneficial for improving APE (lines 5 and 6) but seem to have relatively smaller contributions than interactive representation learning and predicting words to be copied.