Factual State Discovery Benchmark: Evaluating Fact Elicitation in Polish Tax Law

Mateusz Bystroński, Kamil Tagowski, Denis Janiak, Julia Farganus, Lukasz Augustyniak, Monika Kajdanowicz, Tomasz Jan Kajdanowicz


Abstract
Before a tax authority can issue a ruling, it must receive a complete description of the taxpayer’s situation—yet no benchmark measures whether language models can systematically elicit all relevant facts through dialogue.We introduce FSDBench (Factual State Discovery Benchmark), in which a discovery agent questions a simulated taxpayer grounded in a real tax document.The dataset comprises 500 narratives from official Polish tax interpretations, decomposed into 32 874 atomic facts with validated supported precision (97.6%), atomicity (93.8%), and sentence coverage (96.0%).Experiments with four models show that even the best system recovers only 77% of facts on easy samples and under 49% on hard samples after 50 turns.These findings establish conversational fact elicitation as a challenging open problem requiring retrieval-augmented and adaptive questioning strategies.
Anthology ID:
2026.acl-srw.114
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 4: Student Research Workshop)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Santosh T.Y.S.S., Juan Diego Rodriguez, Ona de Gibert
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1262–1279
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URL:
https://preview.aclanthology.org/ingestion-form-platform/2026.acl-srw.114/
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Bibkey:
Cite (ACL):
Mateusz Bystroński, Kamil Tagowski, Denis Janiak, Julia Farganus, Lukasz Augustyniak, Monika Kajdanowicz, and Tomasz Jan Kajdanowicz. 2026. Factual State Discovery Benchmark: Evaluating Fact Elicitation in Polish Tax Law. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 4: Student Research Workshop), pages 1262–1279, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Factual State Discovery Benchmark: Evaluating Fact Elicitation in Polish Tax Law (Bystroński et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingestion-form-platform/2026.acl-srw.114.pdf