A Deep Generative Framework for Paraphrase Generation
Summary
The paper tackles automatic paraphrase generation: given a sentence, produce one or more rewordings that keep its meaning. This is valuable for question answering, retrieval and training-data augmentation. Earlier VAE text models generate sentences unconditionally, and seq2seq systems such as the stacked residual LSTM have no principled way to yield several distinct outputs. The authors build a VAE-LSTM in which both the VAE encoder and the decoder are conditioned on an LSTM encoding of the original sentence. At test time, sampling different latent codes z yields multiple paraphrases, and each one is the top result of its own decoding run. They evaluate on MSCOCO captions, where the model beats the stacked residual LSTM baseline on BLEU, METEOR and TER without hyper-parameter tuning. They also evaluate on the Quora question pairs dataset, where they set a new baseline. Human judges found the outputs mostly readable and relevant. Overall, the work shows that a simple, modular conditional generative model can match or beat more complex seq2seq systems for paraphrasing.
Key points
- The architecture uses four LSTMs: three encoders and one decoder. The original sentence's encoding initializes the decoder, and the latent code z is concatenated into every decoder step.
- There are two supervised variants. VAE-SVG uses separate encoders, while VAE-SVG-eq shares the original-sentence encoder between the encoding and decoding sides. They are compared against an unsupervised VAE, VAE-S and the stacked residual LSTM (Prakash et al. 2016).
- On MSCOCO, VAE-SVG improves TER by about 10 absolute points over the state of the art. Its best results also gain 4.7 points in BLEU and 4 points in METEOR.
- On Quora, VAE-SVG-eq performs best, and beam search helps noticeably. The best variant gains more than 27 BLEU points and more than 19 METEOR points over the unsupervised VAE.
- In human evaluation on a 5-point scale, the system scored as follows (ground truth in parentheses):
- Quora: relevance 3.57 (4.82), readability 4.08 (4.94).
- MSCOCO: relevance 3.0 (3.38), readability 3.84 (4.68).
Interesting ideas
- I1. Condition both sides of a VAE on the source input. This turns a free-text generator into a controllable "variations of X" generator. The same pattern could serve data augmentation for low-resource tasks such as question classification or paraphrase detection.
- I2. Get diversity from latent sampling instead of lower beam ranks. Drawing several z values and taking the top beam output for each avoids the quality drop that comes with taking the k-th beam hypothesis. This is useful wherever several equally good alternatives are needed, for example query expansion.
- I3. Select candidates by similarity to the input, not to the reference. Since references are unavailable at inference, the "best" variant is picked by BLEU or METEOR against the input sentence. This is an honest, deployable way to rerank generated candidates.
- I4. Use a confidence threshold to trade recall for precision. Variants are emitted only when their similarity to the input exceeds a threshold. On Quora this raised BLEU to as much as 55 at 10% recall, a handy knob for high-precision pipelines.
- I5. Read evaluation results against the nature of the data. The authors attribute weaker beam-search gains and lower human relevance on MSCOCO to loosely formed, highly varied captions. This is a reminder to interpret metrics in light of the corpus genre.
Cited by
- Neural Syntactic Preordering for Controlled Paraphrase Generation
- Unsupervised Syntactically Controlled Paraphrase Generation with Abstract Meaning Representations
- ParaAMR: A Large-Scale Syntactically Diverse Paraphrase Dataset by AMR Back-Translation
- Adversarial Example Generation with Syntactically Controlled Paraphrase Networks
- Reformulating Unsupervised Style Transfer as Paraphrase Generation
- Submodular Optimization-based Diverse Paraphrasing and its Effectiveness in Data Augmentation
- Syntax-Guided Controlled Generation of Paraphrases
- Paraphrase Generation with Deep Reinforcement Learning
- Paraphrase Generation as Zero-Shot Multilingual Translation: Disentangling Semantic Similarity from Lexical and Syntactic Diversity
- PAWS: Paraphrase Adversaries from Word Scrambling
Cite
@misc{gupta2017deep,
title = {{A Deep Generative Framework for Paraphrase Generation}},
author = {Gupta, Ankush and Agarwal, Arvind and Singh, Prawaan and Rai, Piyush},
year = {2017},
doi = {10.48550/arxiv.1709.05074},
eprint = {1709.05074},
archivePrefix = {arXiv},
url = {https://doi.org/10.48550/arxiv.1709.05074}
}References
- Bahdanau, D.; Cho, K.; and Bengio, Y. 2014. Neural machine translation by jointly learning to align and translate. arXiv preprint arXiv:1409.0473. β our card
- Bowman, S. R.; Vilnis, L.; Vinyals, O.; Dai, A. M.; Jozefowicz, R.; and Bengio, S. 2015. Generating sentences from a continuous space. arXiv preprint arXiv:1511.06349. β our card
- Chung, J.; Kastner, K.; Dinh, L.; Goel, K.; Courville, A. C.; and Bengio, Y. 2015. A recurrent latent variable model for sequential data. In Advances in neural information processing systems, 2980β2988. find
- Fader, A.; Zettlemoyer, L.; and Etzioni, O. 2014. Open question answering over curated and extracted knowledge bases. In Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining, 1156β1165. ACM. find
- Figueroa, A., and Neumann, G. 2013. Learning to rank effective paraphrases from query logs for community question answering. In AAAI, volume 13, 1099β1105. find
- Goodfellow, I.; Bengio, Y.; and Courville, A. 2016. Deep learning. The MIT Press. find
- Graves, A.; Jaitly, N.; and Mohamed, A.-r. 2013. Hybrid speech recognition with deep bidirectional lstm. In Automatic Speech Recognition and Understanding (ASRU), 2013 IEEE Workshop on, 273β278. IEEE. find
- Hassan, S.; Csomai, A.; Banea, C.; Sinha, R.; and Mihalcea, R. 2007. Unt: Subfinder: Combining knowledge sources for automatic lexical substitution. In Proceedings of the 4th International Workshop on Semantic Evaluations, 410β413. Association for Computational Linguistics. find
- Hochreiter, S., and Schmidhuber, J. 1997. Long short-term memory. Neural computation 9(8):1735β1780. β
- Hu, Z.; Yang, Z.; Liang, X.; Salakhutdinov, R.; and Xing, E. P. 2017. Controllable text generation. arXiv preprint arXiv:1703.00955. β our card
- Kingma, D. P., and Welling, M. 2013. Auto-encoding variational bayes. arXiv preprint arXiv:1312.6114. β our card
- Kingma, D. P., and Welling, M. 2014. Auto-encoding variational bayes. In ICLR. β our card
- Kingma, D. P.; Mohamed, S.; Rezende, D. J.; and Welling, M. 2014. Semi-supervised learning with deep generative models. In Advances in Neural Information Processing Systems, 3581β3589. find
- Kozlowski, R.; Mc-Coy, K. F.; and Vijay-Shanker, K. 2003. Generation of single-sentence paraphrases from predicate/argument structure using lexico-grammatical resources. In Proceedings of the second international workshop on Paraphrasing-Volume 16, 1β8. Association for Computational Linguistics. find
- Lavie, A., and Agarwal, A. 2007. Meteor: An automatic metric for mt evaluation with high levels of correlation with human judgments. In Proceedings of the Second Workshop on Statistical Machine Translation, 228β231. Association for Computational Linguistics. find our card
- Lin, T.-Y.; Maire, M.; Belongie, S.; Bourdev, L.; Girshick, R.; Hays, J.; Perona, P.; Ramanan, D.; Zitnick, C. L.; and Dollar, P. 2014. Microsoft coco: Common objects in context. arXiv preprint arXiv:1405.0312. β our card
- Madnani, N., and Dorr, B. J. 2010. Generating phrasal and sentential paraphrases: A survey of data-driven methods. Computational Linguistics 36(3):341β387. β our card
- Madnani, N.; Tetreault, J.; and Chodorow, M. 2012. Re-examining machine translation metrics for paraphrase identification. In Proceedings of the 2012 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, 182β 190. Association for Computational Linguistics. find our card
- McKeown, K. R. 1983a. Paraphrasing questions using given and new information. Comput. Linguist. 9(1):1β10. find our card
- McKeown, K. R. 1983b. Paraphrasing questions using given and new information. Computational Linguistics 9(1):1β10. find our card
- Papineni, K.; Roukos, S.; Ward, T.; and Zhu, W.-J. 2002. Bleu: a method for automatic evaluation of machine translation. In Proceedings of the 40th annual meeting on association for computational linguistics, 311β318. Association for Computational Linguistics. find our card
- Prakash, A.; Hasan, S. A.; Lee, K.; Datla, V.; Qadir, A.; Liu, J.; and Farri, O. 2016. Neural paraphrase generation with stacked residual lstm networks. arXiv preprint arXiv:1610.03098. β our card
- Quirk, C.; Brockett, C.; and Dolan, W. B. 2004. Monolingual machine translation for paraphrase generation. In EMNLP, 142β149. find our card
- Rezende, D. J.; Mohamed, S.; and Wierstra, D. 2014. Stochastic backpropagation and approximate inference in deep generative models. arXiv preprint arXiv:1401.4082. β our card
- Semeniuta, S.; Severyn, A.; and Barth, E. 2017. A hybrid convolutional variational autoencoder for text generation. arXiv preprint arXiv:1702.02390. β
- Snover, M.; Dorr, B.; Schwartz, R.; Micciulla, L.; and Makhoul, J. 2006. A study of translation edit rate with targeted human annotation. In Proceedings of association for machine translation in the Americas, volume 200. find our card
- Sohn, K.; Lee, H.; and Yan, X. 2015. Learning structured output representation using deep conditional generative models. In Advances in Neural Information Processing Systems, 3483β3491. find
- Sutskever, I.; Vinyals, O.; and Le, Q. V. 2014. Sequence to sequence learning with neural networks. In Advances in neural information processing systems, 3104β3112. β
- Vinyals, O.; Toshev, A.; Bengio, S.; and Erhan, D. 2015. Show and tell: A neural image caption generator. In Proceedings of the IEEE conference on computer vision and pattern recognition, 3156β3164. β our card
- Wubben, S.; Van Den Bosch, A.; and Krahmer, E. 2010. Paraphrase generation as monolingual translation: Data and evaluation. In Proceedings of the 6th International Natural Language Generation Conference, 203β207. Association for Computational Linguistics. find
- Yin, P.; Duan, N.; Kao, B.; Bao, J.; and Zhou, M. 2015. Answering questions with complex semantic constraints on open knowledge bases. In Proceedings of the 24th ACM International on Conference on Information and Knowledge Management, 1301β1310. ACM. find
- Zhao, S.; Niu, C.; Zhou, M.; Liu, T.; and Li, S. 2008. Combining multiple resources to improve smt-based paraphrasing model. In ACL, 1021β1029. find
- Zhao, S.; Lan, X.; Liu, T.; and Li, S. 2009. Application-driven statistical paraphrase generation. In Proceedings of the Joint Conference of the 47th Annual Meeting of the ACL and the 4th International Joint Conference on Natural Language Processing of the AFNLP: Volume 2-Volume 2, 834β842. Association for Computational Linguistics. find our card
This page in Markdown β https://md.research.elamur.ai/free/papers/gupta-2017-deep-generative-framework-paraphrase-generation/