FactReasoner: A Probabilistic Approach to Long-Form Factuality Assessment for Large Language Models

Radu Marinescu, Debarun Bhattacharjya, Junkyu Lee, Tigran T. Tchrakian, Javier Carnerero-Cano, Yufang Hou, Elizabeth M. Daly, Alessandra Pascale


Abstract
Large language models (LLMs) have achieved remarkable success in generative tasks, yet they often fall short in ensuring the factual accuracy of their outputs thus limiting their reliability in real-world applications where correctness is critical. In this paper, we present FactReasoner, a novel neuro-symbolic based factuality assessment framework that employs probabilistic reasoning to evaluate the truthfulness of long-form generated responses. FactReasoner decomposes a response into atomic units, retrieves relevant contextual information from external knowledge sources, and models the logical relationships (e.g., entailment, contradiction) between these units and their contexts using probabilistic encodings. It then estimates the posterior probability that each atomic unit is supported by the retrieved evidence. Our experiments on both labeled and unlabeled benchmark datasets demonstrate that FactReasoner often outperforms state-of-the-art prompt-based methods in terms of factual precision and recall.
Anthology ID:
2025.findings-emnlp.785
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2025
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
14547–14577
Language:
URL:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.785/
DOI:
10.18653/v1/2025.findings-emnlp.785
Bibkey:
Cite (ACL):
Radu Marinescu, Debarun Bhattacharjya, Junkyu Lee, Tigran T. Tchrakian, Javier Carnerero-Cano, Yufang Hou, Elizabeth M. Daly, and Alessandra Pascale. 2025. FactReasoner: A Probabilistic Approach to Long-Form Factuality Assessment for Large Language Models. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 14547–14577, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
FactReasoner: A Probabilistic Approach to Long-Form Factuality Assessment for Large Language Models (Marinescu et al., Findings 2025)
Copy Citation:
PDF:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.785.pdf
Checklist:
 2025.findings-emnlp.785.checklist.pdf