ExPerT: Effective and Explainable Evaluation of Personalized Long-Form Text Generation

Alireza Salemi, Julian Killingback, Hamed Zamani


Abstract
Evaluating personalized text generated by large language models (LLMs) is challenging, as only the LLM user, i.e. prompt author, can reliably assess the output, but re-engaging the same individuals across studies is infeasible. This paper addresses the challenge of evaluating personalized text generation by introducing ExPerT, an explainable reference-based evaluation framework. ExPerT leverages an LLM to extract atomic aspects and their evidences from the generated and reference texts, match the aspects, and evaluate their alignment based on content and writing style—two key attributes in personalized text generation. Additionally, ExPerT generates detailed, fine-grained explanations for every step of the evaluation process, enhancing transparency and interpretability. Our experiments demonstrate that ExPerT achieves a 7.2% relative improvement in alignment with human judgments compared to the state-of-the-art text generation evaluation methods. Furthermore, human evaluators rated the usability of ExPerT’s explanations at 4.7 out of 5, highlighting its effectiveness in making evaluation decisions more interpretable.
Anthology ID:
2025.findings-acl.900
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
17516–17532
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URL:
https://preview.aclanthology.org/landing_page/2025.findings-acl.900/
DOI:
Bibkey:
Cite (ACL):
Alireza Salemi, Julian Killingback, and Hamed Zamani. 2025. ExPerT: Effective and Explainable Evaluation of Personalized Long-Form Text Generation. In Findings of the Association for Computational Linguistics: ACL 2025, pages 17516–17532, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
ExPerT: Effective and Explainable Evaluation of Personalized Long-Form Text Generation (Salemi et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/landing_page/2025.findings-acl.900.pdf