DRT: Deep Reasoning Translation via Long Chain-of-Thought

Jiaan Wang, Fandong Meng, Yunlong Liang, Jie Zhou


Abstract
Recently, O1-like models have emerged as representative examples, illustrating the effectiveness of long chain-of-thought (CoT) in reasoning tasks such as math and coding tasks. In this paper, we introduce DRT, an attempt to bring the success of long CoT to neural machine translation (MT). Specifically, in view of the literature books that might involve similes and metaphors, translating these texts to a target language is very difficult in practice due to cultural differences. In such cases, literal translation often fails to convey the intended meaning effectively. Even for professional human translators, considerable thought must be given to preserving semantics throughout the translation process. To simulate LLMs’ long thought ability in MT, we first mine sentences containing similes or metaphors from existing literature books, and then develop a multi-agent framework to translate these sentences via long thought. In the multi-agent framework, a translator is used to iteratively translate the source sentence under the suggestions provided by an advisor. To ensure the effectiveness of the long thoughts, an evaluator is also employed to quantify the translation quality in each round. In this way, we collect tens of thousands of long-thought MT data, which is used to train our DRT. Using Qwen2.5 and LLama-3.1 as the backbones, DRT models can learn the thought process during machine translation, and outperform vanilla LLMs as well as LLMs which are simply fine-tuning on the paired sentences without long thought, showing its effectiveness.
Anthology ID:
2025.findings-acl.351
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6770–6782
Language:
URL:
https://preview.aclanthology.org/mtsummit-25-ingestion/2025.findings-acl.351/
DOI:
10.18653/v1/2025.findings-acl.351
Bibkey:
Cite (ACL):
Jiaan Wang, Fandong Meng, Yunlong Liang, and Jie Zhou. 2025. DRT: Deep Reasoning Translation via Long Chain-of-Thought. In Findings of the Association for Computational Linguistics: ACL 2025, pages 6770–6782, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
DRT: Deep Reasoning Translation via Long Chain-of-Thought (Wang et al., Findings 2025)
Copy Citation:
PDF:
https://preview.aclanthology.org/mtsummit-25-ingestion/2025.findings-acl.351.pdf