QuestEval: Summarization Asks for Fact-based Evaluation
Written for the Research library (claude-opus-5-5) from the paper text. Original — aclanthology.org/2021.emnlp-main.529.pdf
Summary
Automatic evaluation of summaries remains unreliable. ROUGE and BERTScore correlate weakly with human ratings, depend on reference summaries, and largely ignore whether a summary contradicts its source. Earlier QA-based metrics fell into two camps. Precision-oriented methods ask questions generated from the summary, while recall-oriented ones such as SummaQA ask questions generated from the source. Neither camp outperformed ROUGE. QuestEval combines both directions into a single metric that needs no reference. It uses T5 models for question generation and question answering. Precision checks, via answer F1, whether the source answers summary-derived questions the same way. Recall measures, via answerability confidence, how many source-derived questions the summary can answer. A learned weighter W gives more importance to salient questions, which brings information selection into the score. The final score is the harmonic mean of precision and recall. On SummEval (CNN/Daily Mail) and QAGS-XSUM, QuestEval reaches state-of-the-art correlation with human judgments across consistency, coherence, fluency and relevance. It is particularly strong on factual consistency. Because it requires no reference, it can be applied wherever gold summaries are missing.
Key points
- Two T5-based components drive the metric. A QG module conditions on named entities and nouns as answers. A QA module includes an "unanswerable" output, and generated questions are kept only if the QA model recovers the intended answer.
- The evaluation data is SummEval, which has 12,800 summary-level annotations over outputs of 16 extractive and abstractive systems, plus QAGS-XSUM.
- Training the QA model with negatively sampled unanswerable questions helps. If this step is removed, average correlation falls to 32.4 on SummEval (down from 33.3) and to 28.5 on QAGS-XSUM (down from 30.4).
- The QG beam size matters little. Raising it from K = 1 to K = 20 lifts SummEval Pearson correlation only from 34.4 to 35.6 and leaves system rankings unchanged, so K = 1 is recommended for speed.
- The metric is explainable, since it exposes which salient questions a summary misses or answers inconsistently. Code and models are released at github.com/ThomasScialom/QuestEval.
Cited by
- QAFactEval: Improved QA-Based Factual Consistency Evaluation for Summarization
- Evaluating Large Language Models: A Comprehensive Survey
- TRUE: Re-evaluating Factual Consistency Evaluation
- A Survey on Hallucination in Large Language Models: Principles, Taxonomy, Challenges, and Open Questions
- Survey of Hallucination in Natural Language Generation
- Revisiting the Gold Standard: Grounding Summarization Evaluation with Robust Human Evaluation
- ChatGPT as a Factual Inconsistency Evaluator for Text Summarization
- AlignScore: Evaluating Factual Consistency with A Unified Alignment Function
Cite
@inproceedings{scialom2021questeval,
title = {{QuestEval: Summarization Asks for Fact-based Evaluation}},
author = {Scialom, Thomas and Dray, Paul-Alexis and Lamprier, Sylvain and Piwowarski, Benjamin and Staiano, Jacopo and Wang, Alex and Gallinari, Patrick},
booktitle = {Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing},
year = {2021},
doi = {10.18653/v1/2021.emnlp-main.529},
url = {https://doi.org/10.18653/v1/2021.emnlp-main.529}
}References
- Manik Bhandari, Pranav Gour, Atabak Ashfaq, and Pengfei Liu. 2020. Metrics also disagree in the low scoring range: Revisiting summarization evaluation metrics. In Proceedings of COLING 2020, the 30th International Conference on Computational Linguistics: Technical Papers. find
- The COLING 2020 Organizing Committee. find
- Ping Chen, Fei Wu, Tong Wang, and Wei Ding. 2017. A semantic qa-based approach for text summarization evaluation. arXiv preprint arXiv:1704.06259. — [arXiv:1704.06259](https://arxiv.org/abs/1704.06259) find
- James Clarke and Mirella Lapata. 2010. Discourse constraints for document compression. Computational Linguistics, 36(3):411–441. find
- Jacob Devlin, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. 2018. Bert: Pre-training of deep bidirectional transformers for language understanding. arXiv preprint arXiv:1810.04805. find
- Esin Durmus, He He, and Mona Diab. 2020. Feqa: A question answering evaluation framework for faithfulness assessment in abstractive summarization. arXiv preprint arXiv:2005.03754. find our card
- Matan Eyal, Tal Baumel, and Michael Elhadad. 2019. Question answering as an automatic evaluation metric for news article summarization. arXiv preprint arXiv:1906.00318. find
- Alexander R Fabbri, Wojciech Kryściński, Bryan McCann, Caiming Xiong, Richard Socher, and Dragomir Radev. 2020. Summeval: Re-evaluating summarization evaluation. arXiv preprint arXiv:2007.12626. find
- Tobias Falke, Leonardo FR Ribeiro, Prasetya Ajie Utama, Ido Dagan, and Iryna Gurevych. 2019. find
- EmptyURL-Anonymoussubmission Ranking generated summaries by correctness: An interesting but challenging application for natural language inference. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 2214–2220. find
- Ari Holtzman, Jan Buys, Li Du, Maxwell Forbes, and Yejin Choi. 2019. The curious case of neural text degeneration. arXiv preprint arXiv:1904.09751. find
- Wojciech Kryscinski, Nitish Shirish Keskar, Bryan Mc-Cann, Caiming Xiong, and Richard Socher. 2019. Neural text summarization: A critical evaluation. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Langua… find our card
- Wojciech Kryściński, Bryan McCann, Caiming Xiong, and Richard Socher. 2019. Evaluating the factual consistency of abstractive text summarization. arXiv preprint arXiv:1910.12840. find
- Alon Lavie and Abhaya Agarwal. 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, pages 228–231, Prague, Czech Republic. Association for Computational Linguistics. find our card
- Hwanhee Lee, Thomas Scialom, Seunghyun Yoon, Franck Dernoncourt, and Kyomin Jung. 2021. Qace: Asking questions to evaluate an image caption. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing: Findings. Association for Computational Linguistics. find
- Mike Lewis, Yinhan Liu, Naman Goyal, Marjan Ghazvininejad, Abdelrahman Mohamed, Omer Levy, Ves Stoyanov, and Luke Zettlemoyer. 2019. Bart: Denoising sequence-to-sequence pre-training for natural language generation, translation, and comprehension. arXiv preprint arXiv:1910.13461. find our card
- Wei Li, Xinyan Xiao, Yajuan Lyu, and Yuanzhuo Wang. 2018. Improving neural abstractive document summarization with explicit information selection modeling. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 1787–1796, Brussels, Belgium. Association for C… find
- Chin-Yew Lin. 2004. Rouge: A package for automatic evaluation of summaries. In Text summarization branches out, pages 74–81. find
- Annie Louis and Ani Nenkova. 2013. Automatically assessing machine summary content without a gold standard. Computational Linguistics, 39(2):267– 300. find
- Joshua Maynez, Shashi Narayan, Bernd Bohnet, and Ryan McDonald. 2020. On faithfulness and factuality in abstractive summarization. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics. find
- Ramesh Nallapati, Bowen Zhou, Caglar Gulcehre, Bing Xiang, et al. 2016. Abstractive text summarization using sequence-to-sequence rnns and beyond. arXiv preprint arXiv:1602.06023. find
- Shashi Narayan, Shay B Cohen, and Mirella Lapata. 2018. Don’t give me the details, just the summary! topic-aware convolutional neural networks for extreme summarization. arXiv preprint arXiv:1808.08745. find
- Jekaterina Novikova, Ondřej Dušek, Amanda Cercas Curry, and Verena Rieser. 2017. Why we need new evaluation metrics for nlg. arXiv preprint arXiv:1707.06875. 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. find our card
- Romain Paulus, Caiming Xiong, and Richard Socher. 2017. A deep reinforced model for abstractive summarization. arXiv preprint arXiv:1705.04304. find our card
- Maxime Peyrard. 2019. Studying summarization evaluation metrics in the appropriate scoring range. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 5093– 5100. find
- Colin Raffel, Noam Shazeer, Adam Roberts, Katherine Lee, Sharan Narang, Michael Matena, Yanqi Zhou, Wei Li, and Peter J Liu. 2019. Exploring the limits of transfer learning with a unified text-to-text transformer. arXiv preprint arXiv:1910.10683. find
- Pranav Rajpurkar, Robin Jia, and Percy Liang. 2018. Know what you don’t know: Unanswerable questions for squad. arXiv preprint arXiv:1806.03822. find our card
- Pranav Rajpurkar, Jian Zhang, Konstantin Lopyrev, and Percy Liang. 2016. Squad: 100,000+ questions for machine comprehension of text. arXiv preprint arXiv:1606.05250. find our card
- Clément Rebuffel, Thomas Scialom, Laure Soulier, Benjamin Piwowarski, Sylvain Lamprier, Jacopo Staiano, Geoffrey Scoutheeten, and Patrick Gallinari. 2021. Data-questeval: A referenceless metric for data to text semantic evaluation. In Proceedings of the 2021 Conference on Empirical Methods in Natura… find
- Thomas Scialom, Sylvain Lamprier, Benjamin Piwowarski, and Jacopo Staiano. 2019. Answers unite! unsupervised metrics for reinforced summarization models. arXiv preprint arXiv:1909.01610. find
- Thomas Scialom, Louis Martin, Jacopo Staiano, Éric Villemonte de la Clergerie, and Benoît Sagot. 2021. Rethinking automatic evaluation in sentence simplification. arXiv preprint arXiv:2104.07560. find
- Adam Trischler, Tong Wang, Xingdi Yuan, Justin Harris, Alessandro Sordoni, Philip Bachman, and Kaheer Suleman. 2016. Newsqa: A machine comprehension dataset. arXiv preprint arXiv:1611.09830. find our card
- Ramakrishna Vedantam, C Lawrence Zitnick, and Devi Parikh. 2015. Cider: Consensus-based image description evaluation. In Proceedings of the IEEE conference on computer vision and pattern recognition, pages 4566–4575. find our card
- Alex Wang, Kyunghyun Cho, and Mike Lewis. 2020. Asking and answering questions to evaluate the factual consistency of summaries. arXiv preprint arXiv:2004.04228. find
- Thomas Wolf, Lysandre Debut, Victor Sanh, Julien Chaumond, Clement Delangue, Anthony Moi, Pier-ric Cistac, Tim Rault, Rémi Louf, Morgan Funtow-icz, et al. 2019. Huggingface’s transformers: State-of-the-art natural language processing. ArXiv, pages arXiv–1910. find our card
- Xinnuo Xu, Ondřej Dušek, Jingyi Li, Verena Rieser, and Ioannis Konstas. 2020. Fact-based content weighting for evaluating abstractive summarisation. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 5071–5081. find
- Jingqing Zhang, Yao Zhao, Mohammad Saleh, and Peter J Liu. 2019a. Pegasus: Pre-training with extracted gap-sentences for abstractive summarization. arXiv preprint arXiv:1912.08777. find our card
- Tianyi Zhang, Varsha Kishore, Felix Wu, Kilian Q Weinberger, and Yoav Artzi. 2019b. Bertscore: Evaluating text generation with bert. arXiv preprint arXiv:1904.09675. find
- Zheng Zhao, Shay B Cohen, and Bonnie Webber. 2020. Reducing quantity hallucinations in abstractive summarization. arXiv preprint arXiv:2009.13312. find
- Qingyu Zhou, Nan Yang, Furu Wei, Chuanqi Tan, Hangbo Bao, and Ming Zhou. 2017. Neural question generation from text: A preliminary study. In National CCF Conference on Natural Language Processing and Chinese Computing, pages 662–671. Springer. find
- Implementation details As any NLP task can be framed under the text-to-text paradigm, allowing to remove task specificities from the architecture (Raffel et al., 2019), we build QG, QA, and P , as 6603 find
- Anna Rohrbach, Lisa Anne Hendricks, Kaylee Burns, Trevor Darrell, and Kate Saenko. 2018. Object hallucination in image captioning. arXiv preprint arXiv:1809.02156. find our card