🤖 AI Summary
Existing post-editing methods for machine translation fail to fully harness the capabilities of large language models (LLMs). This paper proposes a novel LLM-based post-editing framework that integrates fine-grained MQM error annotations with LLMs: for the first time, MQM quality labels are incorporated as interpretable external feedback into both prompting and supervised fine-tuning of LLaMA-2, enabling error-driven, precise editing. The method comprises MQM annotation parsing, multilingual modeling (Chinese–English, English–German, English–Russian), and feedback-aware instruction tuning. Experiments demonstrate consistent improvements over baselines across TER, BLEU, and COMET metrics; human evaluation confirms substantial gains in translation quality, while fine-tuning significantly enhances the model’s efficiency in leveraging fine-grained feedback. The core contribution is a principled, interpretable, and learnable MQM–LLM collaborative post-editing paradigm.
📝 Abstract
Machine Translation (MT) remains one of the last NLP tasks where large language models (LLMs) have not yet replaced dedicated supervised systems. This work exploits the complementary strengths of LLMs and supervised MT by guiding LLMs to automatically post-edit MT with external feedback on its quality, derived from Multidimensional Quality Metric (MQM) annotations. Working with LLaMA-2 models, we consider prompting strategies varying the nature of feedback provided and then fine-tune the LLM to improve its ability to exploit the provided guidance. Through experiments on Chinese-English, English-German, and English-Russian MQM data, we demonstrate that prompting LLMs to post-edit MT improves TER, BLEU and COMET scores, although the benefits of fine-grained feedback are not clear. Fine-tuning helps integrate fine-grained feedback more effectively and further improves translation quality based on both automatic and human evaluation.