Comparing Approaches to Automatic Summarization in Less-Resourced Languages
Summary
Neural abstractive summarization performs well for English, but many less-resourced languages have very small training sets, often under 1,000 examples. Palen-Michel and Lignos compare a wide range of strategies on a linguistically diverse group of low-data languages drawn from LR-Sum and XL-Sum.
They fine-tune mT5-base either separately for each language or jointly across all languages. Some runs add synthetic training pairs built from length-filtered Wikipedia articles, using three methods: LexRank extractive targets, self-training and back-summarization. They compare these against zero-shot prompting of smaller LLMs (Mixtral 8x7B, Llama 3 8B, Aya 101) and larger ones (Gemma 3 27B, Llama 3.3 70B, Aya Expanse 32B). They also test a pipeline that translates into English, summarizes there and translates back. Scoring uses ROUGE-1/2/L, BERTScore and reference-free judging with M-Prometheus.
The jointly trained multilingual mT5 baseline beats most alternatives, including zero-shot LLMs, on most metrics. Augmentation helps single-language models but does not match multilingual transfer. LLMs of comparable size differ noticeably, and LLM-as-judge appears unreliable for these languages. The takeaway is that modest multilingual fine-tuning remains a strong, inexpensive option.
Key points
- Data sizes: Training data is tiny for several languages. Combined counts are 383 documents for Shona, 452 for Haitian Creole and 511 for Georgian, while Pashto reaches 31,207 because it appears in both LR-Sum and XL-Sum.
- Wikipedia filtering: Articles were split into sentences with Segment Any Text, and those under five sentences were discarded. This shrinks usable data sharply; for Khmer, only 4,323 articles remain versus 3,888 LR-Sum training examples.
- mT5 configuration: All mT5 models share one setup:
- 3 epochs, learning rate 5e-4, effective batch size 32;
- source/target lengths of 1024/512;
- multilingual upsampling factor 0.5, following the XL-Sum setup.
- English output from LLMs: Zero-shot LLMs sometimes reply in English rather than the target language. Examples include Mixtral and Llama 3 saying they cannot read Lao or asking for the article.
- Released resource: All generated candidate summaries are publicly released on GitHub to support future evaluation research and participatory work with speakers of these languages.
Cite
@inproceedings{palenmichel2026comparing,
title = {{Comparing Approaches to Automatic Summarization in Less-Resourced Languages}},
author = {Palen-Michel, Chester and Lignos, Constantine},
booktitle = {Proceedings of the Fifteenth Language Resources and Evaluation Conference},
year = {2026},
doi = {10.63317/2pi7c62tdqsr},
url = {https://doi.org/10.63317/2pi7c62tdqsr}
}References
- Kamal Al-Sabahi, Zhang Zuping, and Mohammed Nadher. 2018. A hierarchical structured self-attentive model for extractive document summarization (HSSAS). IEEE Access, 6:24205– 24212. find
- Hayastan Avetisyan and David Broneske. 2023. Large language models and low-resource languages: An examination of Armenian NLP. In Findings of the Association for Computational Linguistics: IJCNLP-AACL 2023 (Findings), pages 199–210, Nusa Dua, Bali. Association for Computational Linguistics. find
- Soran Badawi. 2023. KurdSum: A new benchmark dataset for the kurdish text summarization. Natural Language Processing Journal, 5:100043. find
- Edward Beeching, Clémentine Fourrier, Nathan Habib, Sheon Han, Nathan Lambert, Nazneen Rajani, Omar Sanseviero, Lewis Tunstall, and Thomas Wolf. 2023. Open LLM leaderboard (2023-2024). https://huggingface.co/spaces/open-llm-leaderboard-old/open_llm_leaderboard. ↗
- Tommaso Caselli, Roberto Cibin, Costanza Conforti, Enrique Encinas, and Maurizio Teli. 2021. Guiding principles for participatory design-inspired natural language processing. In Proceedings of the 1st Workshop on NLP for Positive Impact, pages 27–35, Online. Association for Computational Linguistics… find
- Hans Christian, Mikhael Pramodana Agus, and Derwin Suhartono. 2016. Single document automatic text summarization using term frequency-inverse document frequency (TF-IDF). ComTech: Computer, Mathematics and Engineering Applications, 7(4):285–294. find
- John Dang, Shivalika Singh, Daniel D’souza, Arash Ahmadian, Alejandro Salamanca, Madeline Smith, Aidan Peppin, Sungjin Hong, Manoj Govindassamy, Terrence Zhao, Sandra Kublik, Meor Amer, Viraat Aryabumi, Jon Ander Campos, Yi-Chern Tan, Tom Kocmi, Florian Strub, Nathan Grinsztajn, Yannis Flet-Berliac,… find our card
- Maxime Darrin, Philippe Formont, Jackie Cheung, and Pablo Piantanida. 2024. COSMIC: Mutual information for task-agnostic summarization evaluation. In Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 12696– 12717, Bangkok, Thailand… find
- Jingfei Du, Edouard Grave, Beliz Gunel, Vishrav Chaudhary, Onur Celebi, Michael Auli, Veselin Stoyanov, and Alexis Conneau. 2021. Self-training improves pre-training for natural language understanding. In Proceedings of the 2021 Conference of the North American Chapter of the Association for Computa… find
- Abhimanyu Dubey, Abhinav Jauhri, Abhinav Pandey, Abhishek Kadian, Ahmad Al-Dahle, Aiesha Letman, Akhil Mathur, Alan Schelten, Amy Yang, Angela Fan, et al. 2024. The Llama 3 herd of models. arXiv preprint arXiv:2407.21783. find
- Günes Erkan and Dragomir R. Radev. 2004. LexRank: graph-based lexical centrality as salience in text summarization. J. Artif. Int. Res., 22(1):457–479. find
- Clémentine Fourrier, Nathan Habib, Alina Lozovskaya, Konrad Szafer, and Thomas Wolf. 2024. Open LLM leaderboard v2. https://huggingface.co/spaces/open-llm-leaderboard/open_llm_leaderboard. ↗
- Markus Frohmann, Igor Sterner, Ivan Vulić, Benjamin Minixhofer, and Markus Schedl. 2024. Segment any text: A universal approach for robust, efficient and adaptable sentence segmentation. find
- Jinlan Fu, See-Kiong Ng, Zhengbao Jiang, and Pengfei Liu. 2024. GPTScore: Evaluate as you desire. In Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers), pages 6556–6576, Mexico City, M… find
- Gemma Team, Aishwarya Kamath, Johan Ferret, Shreya Pathak, Nino Vieillard, Ramona Merhej, Sarah Perrin, Tatiana Matejovicova, Alexandre Ramé, Morgane Rivière, Louis Rouillard, Thomas Mesnard, Geoffrey Cideron, Jean bastien Grill, Sabela Ramos, Edouard Yvinec, Michelle Casbon, Etienne Pot, Ivo Penche… find
- George Giannakopoulos, John M Conroy, Jeff Kubina, Peter A Rankel, Elena Lloret, Josef Steinberger, Marina Litvak, and Benoit Favre. 2017. find
- MultiLing 2017 overview. find
- George Giannakopoulos, Jeff Kubina, John Conroy, Josef Steinberger, Benoit Favre, Mijail Kabadjov, Udo Kruschwitz, and Massimo Poesio. 2015. find
- MultiLing 2015: multilingual summarization of single and multi-documents, on-line fora, and call-center conversations. In Proceedings of the 16th Annual Meeting of the Special Interest Group on Discourse and Dialogue, pages 270– 274. find
- Tahmid Hasan, Abhik Bhattacharjee, Md. Saiful Islam, Kazi Mubasshir, Yuan-Fang Li, Yong-Bin Kang, M. Sohel Rahman, and Rifat Shahriyar. 2021. XL-sum: Large-scale multilingual abstractive summarization for 44 languages. In Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021, pa… find
- Phan Viet Hoang. 2020. Khmer natural language processing toolkit. https://github.com/VietHoang1512/khmer-nltk. ↗
- Wan-Ting Hsu, Chieh-Kai Lin, Ming-Ying Lee, Kerui Min, Jing Tang, and Min Sun. 2018. A unified model for extractive and abstractive summarization using inconsistency loss. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 132–14… find
- Neslihan Iskender, Tim Polzehl, and Sebastian Möller. 2021. Reliability of human evaluation for text summarization: Lessons learned and challenges ahead. In Proceedings of the Workshop on Human Evaluation of NLP Systems (HumEval), pages 86–96, Online. Association for Computational Linguistics. find
- Albert Q. Jiang, Alexandre Sablayrolles, Antoine Roux, Arthur Mensch, Blanche Savary, Chris Bamford, Devendra Singh Chaplot, Diego de las Casas, Emma Bou Hanna, Florian Bressand, Gianna Lengyel, Guillaume Bour, Guillaume Lample, Lélio Renard Lavaud, Lucile Saulnier, Marie-Anne Lachaux, Pierre Stock,… find
- Giannis Karamanolakis, Subhabrata Mukherjee, Guoqing Zheng, and Ahmed Hassan Awadallah. 2021. Self-training with weak supervision. In Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, pages 845–863, Online.… find
- Seungone Kim, Juyoung Suk, Shayne Longpre, Bill Yuchen Lin, Jamin Shin, Sean Welleck, Graham Neubig, Moontae Lee, Kyungjae Lee, and Minjoon Seo. 2024. Prometheus 2: An open source language model specialized in evaluating other language models. In Proceedings of the 2024 Conference on Empirical Metho… find our card
- Wojciech Kryscinski, Nitish Shirish Keskar, Bryan McCann, 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 Languag… find our card
- Chin-Yew Lin. 2004. ROUGE: A package for automatic evaluation of summaries. In Text Summarization Branches Out, pages 74–81, Barcelona, Spain. Association for Computational Linguistics. find
- Yixin Liu, Pengfei Liu, Dragomir Radev, and Graham Neubig. 2022. BRIO: Bringing order to abstractive summarization. In Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 2890–2903, Dublin, Ireland. Association for Computational Ling… find our card
- Hans Peter Luhn. 1958. The automatic creation of literature abstracts. IBM Journal of research and development, 2(2):159–165. find
- Kelly Marchisio, Saurabh Dash, Hongyu Chen, Dennis Aumiller, Ahmet Üstün, Sara Hooker, and Sebastian Ruder. 2024. How does quantization affect multilingual LLMs? arXiv preprint arXiv:2407.03211. find
- Yu Meng, Yunyi Zhang, Jiaxin Huang, Xuan Wang, Yu Zhang, Heng Ji, and Jiawei Han. 2021. Distantly-supervised named entity recognition with noise-robust learning and language model augmented self-training. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, page… find
- Chester Palen-Michel and Constantine Lignos. 2023. LR-sum: Summarization for less-resourced languages. In Findings of the Association for Computational Linguistics: ACL 2023, pages 6829–6844, Toronto, Canada. Association for Computational Linguistics. find
- Shantipriya Parida and Petr Motlicek. 2019. Abstract text summarization: A low resource challenge. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP), pages 5994–5998, Hong… find
- José Pombal, Dongkeun Yoon, Patrick Fernandes, Ian Wu, Seungone Kim, Ricardo Rei, Graham Neubig, and André F. T. Martins. 2025. Mprometheus: A suite of open multilingual LLM judges. find
- Peng Qi, Yuhao Zhang, Yuhui Zhang, Jason Bolton, and Christopher D. Manning. 2020. Stanza: A python natural language processing toolkit for many human languages. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics: System Demonstrations, pages 101–108, Online.… find our card
- Dragomir R Radev, Sasha Blair-Goldensohn, and Zhu Zhang. 2001. Experiments in single and multidocument summarization using MEAD. In First document understanding conference, pages 1–7. find
- Alexander M. Rush, Sumit Chopra, and Jason Weston. 2015. A neural attention model for abstractive sentence summarization. In Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing, pages 379–389, Lisbon, Portugal. Association for Computational Linguistics. find
- Alex Salcianu, Andy Golding, Anton Bakalov, Chris Alberti, Daniel Andor, David Weiss, Emily Pitler, Greg Coppola, Jason Riesa, Kuzman Ganchev, Michael Ringgaard, Nan Hua, Ryan McDonald, Slav Petrov, Stefan Istrate, and Terry Koo. 2016. Compact Language Detector v3 (CLD3). https://github.com/google/… ↗
- Thomas Scialom, Paul-Alexis Dray, Sylvain Lamprier, Benjamin Piwowarski, and Jacopo Staiano. 2020. MLSUM: The multilingual summarization corpus. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 8051–8067, Online. Association for Computational L… find
- 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. Association for Comput… find
- Rico Sennrich, Barry Haddow, and Alexandra Birch. 2016. Improving neural machine translation models with monolingual data. In Proceedings of the 54th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 86–96, Berlin, Germany. Association for Computational L… find
- Tianxiang Sun, Junliang He, Xipeng Qiu, and Xuanjing Huang. 2022. BERTScore is unfair: On social bias in language model-based metrics for text generation. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 3726–3739, Abu Dhabi, United Arab Emirates. Asso… find
- Hasan Tanvir, Claudia Kittask, Sandra Eiche, and Kairit Sirts. 2021. EstBERT: A pretrained language-specific BERT for Estonian. In Proceedings of the 23rd Nordic Conference on Computational Linguistics (NoDaLiDa), pages 11–19, Reykjavik, Iceland (Online). Linköping University Electronic Press, Swede… find
- Robert J Tibshirani and Bradley Efron. 1993. An introduction to the bootstrap. Monographs on statistics and applied probability, 57(1):1–436. find
- Elsbeth Turcan, David Wan, Faisal Ladhak, Petra Galuscakova, Sukanta Sen, Svetlana Tchistiakova, Weijia Xu, Marine Carpuat, Kenneth Heafield, Douglas Oard, and Kathleen McKeown. 2022. Constrained regeneration for cross-lingual query-focused extractive summarization. In Proceedings of the 29th Intern… find
- Ahmet Üstün, Viraat Aryabumi, Zheng Yong, Wei-Yin Ko, Daniel D’souza, Gbemileke Onilude, Neel Bhandari, Shivalika Singh, Hui-Lee Ooi, Amr Kayid, Freddie Vargus, Phil Blunsom, Shayne Longpre, Niklas Muennighoff, Marzieh Fadaee, Julia Kreutzer, and Sara Hooker. 2024. Aya model: An instruction finetune… find our card
- Oleg Vasilyev, Vedant Dharnidharka, and John Bohannon. 2020. Fill in the BLANC: Human-free quality estimation of document summaries. In Proceedings of the First Workshop on Evaluation and Comparison of NLP Systems, pages 11–20, Online. Association for Computational Linguistics. find
- Antti Virtanen, Jenna Kanerva, Rami Ilo, Jouni Luoma, Juhani Luotolahti, Tapio Salakoski, Filip Ginter, and Sampo Pyysalo. 2019. Multilingual is not enough: BERT for finnish. find our card
- Danqing Wang, Jiaze Chen, Hao Zhou, Xipeng Qiu, and Lei Li. 2021. Contrastive aligned joint learning for multilingual summarization. In Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021, pages 2739–2750, Online. Association for Computational Linguistics. find
- Thomas Wolf, Lysandre Debut, Victor Sanh, Julien Chaumond, Clement Delangue, Anthony Moi, Pierric Cistac, Tim Rault, Remi Louf, Morgan Funtowicz, Joe Davison, Sam Shleifer, Patrick von Platen, Clara Ma, Yacine Jernite, Julien Plu, Canwen Xu, Teven Le Scao, Sylvain Gugger, Mariama Drame, Quentin Lhoe… find our card
- Linting Xue, Noah Constant, Adam Roberts, Mihir Kale, Rami Al-Rfou, Aditya Siddhant, Aditya Barua, and Colin Raffel. 2021. mT5: A massively multilingual pre-trained text-to-text transformer. In Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Ling… find
- An Yang, Baosong Yang, Binyuan Hui, Bo Zheng, Bowen Yu, Chang Zhou, Chengpeng Li, Chengyuan Li, Dayiheng Liu, Fei Huang, Guanting Dong, Haoran Wei, Huan Lin, Jialong Tang, Jialin Wang, Jian Yang, Jianhong Tu, Jianwei Zhang, Jianxin Ma, Jin Xu, Jingren Zhou, Jinze Bai, Jinzheng He, Junyang Lin, Kai D… find
- Jingqing Zhang, Yao Zhao, Mohammad Saleh, and Peter Liu. 2020a. PEGASUS: Pre-training with extracted gap-sentences for abstractive summarization. In Proceedings of the 37th International Conference on Machine Learning, volume 119 of Proceedings of Machine Learning Research, pages 11328–11339. PMLR. find our card
- Tianyi Zhang, Varsha Kishore, Felix Wu, Kilian Q. Weinberger, and Yoav Artzi. 2020b. Bertscore: Evaluating text generation with BERT. find
- Tianyi Zhang, Faisal Ladhak, Esin Durmus, Percy Liang, Kathleen McKeown, and Tatsunori B. Hashimoto. 2024. Benchmarking large language models for news summarization. Transactions of the Association for Computational Linguistics, 12:39–57. find our card
- Language Resource References Tahmid Hasan, Abhik Bhattacharjee, Md. Saiful Islam, Kazi Mubasshir, Yuan-Fang Li, Yong-Bin Kang, M. Sohel Rahman, and Rifat Shahriyar. 2021. XL-sum: Large-scale multilingual abstractive summarization for 44 languages. In Findings of the Association for Computational Lin… find
- Khanh Nguyen and Hal Daumé III. 2019. Global Voices: Crossing borders in automatic news summarization. In Proceedings of the 2nd Workshop on New Frontiers in Summarization, pages 90– 97, Hong Kong, China. Association for Computational Linguistics. find
- Chester Palen-Michel, June Kim, and Constantine Lignos. 2022. Multilingual open text release 1: Public domain news in 44 languages. In Proceedings of the Thirteenth Language Resources and Evaluation Conference, pages 2080–2089, Marseille, France. European Language Resources Association. find
- Chester Palen-Michel and Constantine Lignos. 2023. LR-sum: Summarization for less-resourced languages. In Findings of the Association for Computational Linguistics: ACL 2023, pages 6829–6844, Toronto, Canada. Association for Computational Linguistics. find
- Daniel Varab and Natalie Schluter. 2021. MassiveSumm: a very large-scale, very multilingual, news summarisation dataset. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 10150– 10161, Online and Punta Cana, Dominican Republic. Association for Computati… find
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