A Deep Reinforced Model for Zero-Shot Cross-Lingual Summarization with Bilingual Semantic Similarity Rewards

Zi-Yi Dou, Sachin Kumar, Yulia Tsvetkov


Abstract
Cross-lingual text summarization aims at generating a document summary in one language given input in another language. It is a practically important but under-explored task, primarily due to the dearth of available data. Existing methods resort to machine translation to synthesize training data, but such pipeline approaches suffer from error propagation. In this work, we propose an end-to-end cross-lingual text summarization model. The model uses reinforcement learning to directly optimize a bilingual semantic similarity metric between the summaries generated in a target language and gold summaries in a source language. We also introduce techniques to pre-train the model leveraging monolingual summarization and machine translation objectives. Experimental results in both English–Chinese and English–German cross-lingual summarization settings demonstrate the effectiveness of our methods. In addition, we find that reinforcement learning models with bilingual semantic similarity as rewards generate more fluent sentences than strong baselines.
Anthology ID:
2020.ngt-1.7
Volume:
Proceedings of the Fourth Workshop on Neural Generation and Translation
Month:
July
Year:
2020
Address:
Online
Editors:
Alexandra Birch, Andrew Finch, Hiroaki Hayashi, Kenneth Heafield, Marcin Junczys-Dowmunt, Ioannis Konstas, Xian Li, Graham Neubig, Yusuke Oda
Venue:
NGT
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
60–68
Language:
URL:
https://aclanthology.org/2020.ngt-1.7
DOI:
10.18653/v1/2020.ngt-1.7
Bibkey:
Cite (ACL):
Zi-Yi Dou, Sachin Kumar, and Yulia Tsvetkov. 2020. A Deep Reinforced Model for Zero-Shot Cross-Lingual Summarization with Bilingual Semantic Similarity Rewards. In Proceedings of the Fourth Workshop on Neural Generation and Translation, pages 60–68, Online. Association for Computational Linguistics.
Cite (Informal):
A Deep Reinforced Model for Zero-Shot Cross-Lingual Summarization with Bilingual Semantic Similarity Rewards (Dou et al., NGT 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.ngt-1.7.pdf
Video:
 http://slideslive.com/38929820
Code
 zdou0830/crosslingual_summarization_semantic