Sen Song


2020

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Unsupervised Paraphrasing by Simulated Annealing
Xianggen Liu | Lili Mou | Fandong Meng | Hao Zhou | Jie Zhou | Sen Song
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

We propose UPSA, a novel approach that accomplishes Unsupervised Paraphrasing by Simulated Annealing. We model paraphrase generation as an optimization problem and propose a sophisticated objective function, involving semantic similarity, expression diversity, and language fluency of paraphrases. UPSA searches the sentence space towards this objective by performing a sequence of local editing. We evaluate our approach on various datasets, namely, Quora, Wikianswers, MSCOCO, and Twitter. Extensive results show that UPSA achieves the state-of-the-art performance compared with previous unsupervised methods in terms of both automatic and human evaluations. Further, our approach outperforms most existing domain-adapted supervised models, showing the generalizability of UPSA.