Syntax-Guided Controlled Generation of Paraphrases
Written for the Research library (claude-opus-5-5) from the paper text. Original — aclanthology.org/2020.tacl-1.22.pdf
Summary
Syntactically controlled paraphrasing rewrites a sentence so its meaning stays intact while its structure follows a separate exemplar sentence. This is useful for tasks such as adapting text to readers' literacy levels or augmenting training data. Earlier systems either flattened the exemplar's constituency tree into a token sequence (SCPN) or learned latent syntax with a variational autoencoder (CGEN). Both approaches lose structural detail and tend to mimic the exemplar's length, which often yields truncated, ungrammatical outputs. The authors propose SGCP, an end-to-end model with three parts: a GRU sentence encoder, an RNN-style encoder that reads the exemplar's full constituency parse, and a pointer-generator decoder that receives a span-level syntactic signal at each step. Pruning the parse at a chosen height lets users adjust how strictly the output copies the exemplar's structure. On English datasets, including a new benchmark built from Quora Question Pairs, SGCP outperforms SCPN and CGEN in both automatic and human evaluations. Its outputs follow the target syntax while staying faithful to the source and grammatical.
Key points
- Architecture: a GRU semantic encoder, a modified RNN tree encoder over exemplar parses produced by the Stanford CoreNLP toolkit, and a novel pointer-generator decoder. Leaf tokens of the exemplar are dropped so that its meaning does not leak into the output.
- Adjustable granularity: the exemplar tree is cut at height H. The paper's examples with H = 4 to 7 show outputs moving progressively closer to the exemplar's form.
- Faster inference than SCPN: SGCP generates in one pass, whereas SCPN first expands templates into full linearized parses and then generates text. CGEN relies on POS tags only during training.
- Released resources: a Quora Question Pairs–derived evaluation set and source code at github.com/malllabiisc/SGCP. The paper appeared in TACL vol. 8, pp. 330–345.
- Limitations: the model does not check whether a source sentence and an exemplar are compatible, which can produce nonsensical paraphrases (e.g., "is career useful in software ?"). Like the baselines, it suffers from dataset bias and does not transfer directly to new domains.
Cited by
- A Survey of Data Augmentation Approaches for NLP
- Unsupervised Syntactically Controlled Paraphrase Generation with Abstract Meaning Representations
- ParaAMR: A Large-Scale Syntactically Diverse Paraphrase Dataset by AMR Back-Translation
- Paraphrasing evades detectors of AI-generated text, but retrieval is an effective defense
Cite
@article{kumar2020syntax,
title = {{Syntax-Guided Controlled Generation of Paraphrases}},
author = {Kumar, Ashutosh and Ahuja, Kabir and Vadapalli, Raghuram and Talukdar, Partha},
journal = {Transactions of the Association for Computational Linguistics},
year = {2020},
doi = {10.1162/tacl\_a\_00318},
url = {https://doi.org/10.1162/tacl_a_00318}
}References
- Roee Aharoni and Yoav Goldberg. 2017. Towards string-to-tree neural machine translation. In Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers), pages 132–140. Vancouver, Canada. Association for Computational Linguistics. find our card
- Richard Chase Anderson and Alice Davison. 1986. Conceptual and empirical bases of readability formulas. Center for the Study of Reading Technical Report; no. 392. find
- Dzmitry Bahdanau, Kyunghyun Cho, and Yoshua Bengio. 2014. Neural machine translation by jointly learning to align and translate. arXiv preprint arXiv:1409.0473. ↗ our card
- Mingda Chen, Qingming Tang, Sam Wiseman, and Kevin Gimpel. 2019b. A multi-task approach for disentangling syntax and semantics in sentence representations. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 2453–2464, Minneapolis, Minnesota. Association for Computational Linguistics. find
- Junyoung Chung, Caglar Gulcehre, Kyunghyun Cho, and Yoshua Bengio. 2014. Empirical evaluation of gated recurrent neural networks on sequence modeling. In NIPS 2014 Workshop on Deep Learning, December 2014. find
- Satanjeev Banerjee and Alon Lavie. 2005. METEOR: An automatic metric for MT evaluation with improved correlation with human judgments. In Proceedings of the ACL Workshop on Intrinsic and Extrinsic Evaluation Measures for Machine Translation and/or Summarization, pages 65–72. find our card
- Herbert H. Clark and Eve V. Clark. 1968. Semantic distinctions and memory for complex sentences. Quarterly Journal of Experimental Psychology, 20(2):129–138. find
- Rotem Dror, Gili Baumer, Segev Shlomov, and Roi Reichart. 2018. The hitchhiker’s guide to testing statistical significance in natural language processing. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1383–1392, Melbourne, Australia. Association for Computational Linguistics. find
- Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers), pages 1875–1885, New Orleans, Louisiana. Association for Computational Linguistics. find
- Evelyn Walker Katz and Sandor B. Brent. 1968. Understanding connectives. Journal of Memory and Language, 7(2):501. find
- Ankush Gupta, Arvind Agarwal, Prawaan Singh, and Piyush Rai. 2018. A deep generative framework for paraphrase generation. In Thirty-Second AAAI Conference on Artificial Intelligence. find
- Diederik P. Kingma and Jimmy Ba. 2014. Adam: A method for stochastic optimization. arXiv preprint arXiv:1412.6980. ↗
- Diederik P. Kingma and Max Welling. 2014. Auto-encoding variational bayes. In Proceedings of ICLR. find our card
- Samer Hassan, Andras Csomai, Carmen Banea, Ravi Sinha, and Rada Mihalcea. 2007. Unt: Subfinder: Combining knowledge sources for automatic lexical substitution. In Proceedings of the 4th International Workshop on Semantic Evaluations, pages 410–413. Association for Computational Linguistics. find
- Ashutosh Kumar, Satwik Bhattamishra, Manik Bhandari, and Partha Talukdar. 2019. Submodular optimization-based diverse paraphrasing and its effectiveness in data augmentation. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 3609–3619, Minneapolis, Minnesota. Association for Computational Linguistics. find our card
- Dan Hendrycks and Kevin Gimpel. 2016. Gaussian error linear units (gelus). arXiv preprint arXiv:1606.08415. ↗
- Sepp Hochreiter and Jürgen Schmidhuber. 1997. Long short-term memory. Neural Computation, 9(8):1735–1780. ↗
- Zhiting Hu, Zichao Yang, Xiaodan Liang, Ruslan Salakhutdinov, and Eric P Xing. 2017. Toward controlled generation of text. In Proceedings of the 34th International Conference on Machine Learning-Volume 70, pages 1587–1596. JMLR.org. find our card
- Elena T. Levy. 2003. The roots of coherence in discourse. Human Development, 46(4): 169–188. find
- Jiwei Li, Michel Galley, Chris Brockett, Jianfeng Gao, and Bill Dolan. 2016. A diversity-promoting objective function for neural conversation models. In Proceedings of the 2016 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, pages 110–119. find our card
- Judith W. Irwin. 1980. The effects of explicitness and clause order on the comprehension of reversible causal relationships. Reading Research Quarterly, pages 477–488. find
- Phillip Isola, Jun-Yan Zhu, Tinghui Zhou, and Alexei A. Efros. 2017. Image-to-image translation with conditional adversarial networks. In Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pages 1125–1134. find
- Zichao Li, Xin Jiang, Lifeng Shang, and Hang Li. 2018. Paraphrase generation with deep reinforcement learning. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 3865–3878, Brussels, Belgium. Association for Computational Linguistics. find our card
- Mohit Iyyer, John Wieting, Kevin Gimpel, and Luke Zettlemoyer. 2018. Adversarial example generation with syntactically controlled paraphrase networks. In Proceedings of the 2018 find our card
- Zichao Li, Xin Jiang, Lifeng Shang, and Qun Liu. 2019. Decomposable neural paraphrase and Oladimeji Farri. 2016. Neural paraphrase generation with stacked residual LSTM networks. In Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers, pages 2923–2934, Osaka, Japan. find
- The COLING 2016 Organizing Committee. generation. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 3403–3414, Florence, Italy. Association for Computational Linguistics. find
- Chin-Yew Lin. 2004. ROUGE: A package for automatic evaluation of summaries. In Text Summarization Branches Out. https://www.aclweb.org/anthology/W04-1013. ↗
- Chris Quirk, Chris Brockett, and William Dolan. 2004. Monolingual machine translation for paraphrase generation. In Proceedings of the 2004 Conference on Empirical Methods in Natural Language Processing, pages 142–149. find our card
- Yinhan Liu, Myle Ott, Naman Goyal, Jingfei Du, Mandar Joshi, Danqi Chen, Omer Levy, Mike Lewis, Luke Zettlemoyer, and Veselin Stoyanov. 2019. Roberta: A robustly optimized bert pretraining approach. arXiv preprint arXiv: 1907.11692. ↗
- Ehud Reiter. 2018. A structured review of the validity of BLEU. Computational Linguistics, 44(3):393–401. find our card
- Nitin Madnani and Bonnie J. Dorr. 2010. Generating phrasal and sentential paraphrases: A survey of data-driven methods. Computational Linguistics, 36(3):341–387. find our card
- Abigail See, Peter J. Liu, and Christopher D. Manning. 2017. Get to the point: Summarization with pointer-generator networks. In Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1073–1083, Vancouver, Canada. find
- Christopher D. Manning, Mihai Surdeanu, John Bauer, Jenny Finkel, Steven J. Bethard, and David McClosky. 2014. The Stanford CoreNLP natural language processing toolkit. In Association for Computational Linguistics (ACL) System Demonstrations, pages 55–60. find our card
- Rico Sennrich, Barry Haddow, and Alexandra Birch. 2016. Neural machine translation of rare words with subword units. In Proceedings of the 54th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1715–1725, Berlin, Germany. find
- Kathleen R. McKeown. 1983. Paraphrasing questions using given and new information. Computational Linguistics, 9(1):1–10. find
- Kishore Papineni, Salim Roukos, Todd Ward, and Wei-Jing Zhu. 2002. BLEU: A method for automatic evaluation of machine translation. In Proceedings of the 40th Annual Meeting of the Association for Computational Linguistics, pages 311–318, Philadelphia, Pennsylvania, USA. Association for Computational Linguistics. ↗ our card
- Tianxiao Shen, Tao Lei, Regina Barzilay, and Tommi Jaakkola. 2017. Style transfer from non-parallel text by cross-alignment. In Advances in Neural Information Processing Systems, pages 6830–6841. find our card
- Xing Shi, Inkit Padhi, and Kevin Knight. 2016. Does string-based neural MT learn source syntax? In Proceedings of the 2016 Conference on Empirical Methods in Natural Language Processing, pages 1526–1534, Austin, Texas. Association for Computational Linguistics. find our card
- Hao Peng, Ankur Parikh, Manaal Faruqui, Bhuwan Dhingra, and Dipanjan Das. 2019. Text generation with exemplar-based adaptive decoding. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 2555–2565, Minneapolis, Minnesota. Association for Computational Linguistics. find
- Advaith Siddharthan. 2014. A survey of research on text simplification. ITL-International Journal of Applied Linguistics, 165(2):259–298. find
- Felix Stahlberg, Eva Hasler, Aurelien Waite, and Bill Byrne. 2016. Syntactically guided neural machine translation. In Proceedings of the 54th Annual Meeting of the Association for Aaditya Prakash, Sadid A. Hasan, Kathy Lee, Vivek Datla, Ashequl Qadir, Joey Liu, Computational Linguistics (Volume 2: Short Papers), pages 299–305. Natural Language Generation Conference, pages 203–207. Association for Computational Linguistics. find
- Kai Sheng Tai, Richard Socher, and Christopher D. Manning. 2015. Improved semantic representations from tree-structured long short-term memory networks. In Proceedings of the 53rd Annual Meeting of the Association for Computational Linguistics and the 7th International Joint Conference on Natural Language Processing (Volume 1: Long Papers), pages 1556–1566. find
- Xuewen Yang, Yingru Liu, Dongliang Xie, Xin Wang, and Niranjan Balasubramanian. 2019. Latent part-of-speech sequences for neural machine translation. find
- Zichao Yang, Zhiting Hu, Chris Dyer, Eric P. Xing, and Taylor Berg-Kirkpatrick. 2018. Unsupervised text style transfer using language models as discriminators. In Advances in Neural Information Processing Systems, pages 7287–7298. find
- Oriol Vinyals, Meire Fortunato, and Navdeep Jaitly. 2015. Pointer networks. In Advances in Neural Information Processing Systems, pages 2692–2700. find
- Kaizhong Zhang and Dennis Shasha. 1989. Simple fast algorithms for the editing distance between trees and related problems. SIAM Journal on Computing, 18(6):1245–1262. find
- Oriol Vinyals and Quoc Le. 2015. A neural conversational model. arXiv preprint arXiv: 1506.05869. ↗ our card
- Yuan Zhang, Jason Baldridge, and Luheng He. 2019. PAWS: Paraphrase adversaries from word scrambling. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 1298–1308. find our card
- John Wieting and Kevin Gimpel. 2018. Paranmt-50m: Pushing the limits of paraphrastic sentence embeddings with millions of machine translations. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 451–462. find our card
- Shiqi Zhao, Cheng Niu, Ming Zhou, Ting Liu, and Sheng Li. 2008. Combining multiple resources to improve SMT-based paraphrasing model. Proceedings of ACL-08: HLT. pages 1021–1029. find
- Sander Wubben, Antal Van Den Bosch, and Emiel Krahmer. 2010. Paraphrase generation as monolingual translation: Data and evaluation. In Proceedings of the 6th International find