Assessing LLMs for Zero-shot Abstractive Summarization Through the Lens of Relevance Paraphrasing

Hadi Askari, Anshuman Chhabra, Muhao Chen, Prasant Mohapatra


Abstract
Large Language Models (LLMs) have achieved state-of-the-art performance at zero-shot generation of abstractive summaries for given articles. However, little is known about the robustness of such a process of zero-shot summarization.To bridge this gap, we propose *relevance paraphrasing*, a simple strategy that can be used to measure the robustness of LLMs as summarizers. The relevance paraphrasing approach identifies the most *relevant* sentences that contribute to generating an ideal summary, and then *paraphrases* these inputs to obtain a minimally perturbed dataset. Then, by evaluating model performance for summarization on both the original and perturbed datasets, we can assess the LLM’s one aspect of robustness. We conduct extensive experiments with relevance paraphrasing on 4 diverse datasets, as well as 4 LLMs of different sizes (GPT-3.5-Turbo, Llama-2-13B, Mistral-7B-v1, and Dolly-v2-7B). Our results indicate that LLMs are not consistent summarizers for the minimally perturbed articles, necessitating further improvements.
Anthology ID:
2025.findings-naacl.116
Volume:
Findings of the Association for Computational Linguistics: NAACL 2025
Month:
April
Year:
2025
Address:
Albuquerque, New Mexico
Editors:
Luis Chiruzzo, Alan Ritter, Lu Wang
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
2187–2201
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URL:
https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.116/
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Cite (ACL):
Hadi Askari, Anshuman Chhabra, Muhao Chen, and Prasant Mohapatra. 2025. Assessing LLMs for Zero-shot Abstractive Summarization Through the Lens of Relevance Paraphrasing. In Findings of the Association for Computational Linguistics: NAACL 2025, pages 2187–2201, Albuquerque, New Mexico. Association for Computational Linguistics.
Cite (Informal):
Assessing LLMs for Zero-shot Abstractive Summarization Through the Lens of Relevance Paraphrasing (Askari et al., Findings 2025)
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https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.116.pdf