RSAT: Structured Attribution Makes Small Language Models Faithful Table Reasoners

Jugal Gajjar, Kamalasankari Subramaniakuppusamy


Abstract
When a language model answers a table question, users have no way to verify which cells informed which reasoning steps. We introduce RSAT, a method that trains small language models (SLMs, 1–8B) to produce step-by-step reasoning with cell-level citations grounded in table evidence. Phase 1 (SFT) teaches a structured JSON output format from verified reasoning traces. Phase 2 (GRPO) optimizes a composite reward centered on NLI-based faithfulness, alongside citation validity and parsimony. Across six models from two families—Qwen2.5 (1.5B/3B/7B) and Llama3 (1B/3B/8B)—RSAT improves faithfulness 3.7× over SFT alone (0.2240.826), with near-perfect citation validity (0.992). Post-hoc attribution collapses below 13% format success, confirming that attribution must be integrated into reasoning, not retrofitted. Ablations show the faithfulness reward is essential: removing it drops faithfulness from 0.97 to 0.03.
Anthology ID:
2026.surgellm-1.7
Volume:
Proceedings of the First Workshop on Structured Understanding, Retrieval, and Generation in the LLM Era (SURGeLLM 2026)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Vivek Gupta, Kaize Ding, Harsha Kokel, Yue Zhao, Amit Agarwal, Yu Wang, Michael Glass, Yu Zhang, Kavitha Srinivas, Xiusi Chen, Oktie Hassanzadeh, Qi Zhu, Shuaichen Chang, Yuan Luo
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SURGeLLM | WS
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Publisher:
Association for Computational Linguistics
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Pages:
119–131
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URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.surgellm-1.7/
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Cite (ACL):
Jugal Gajjar and Kamalasankari Subramaniakuppusamy. 2026. RSAT: Structured Attribution Makes Small Language Models Faithful Table Reasoners. In Proceedings of the First Workshop on Structured Understanding, Retrieval, and Generation in the LLM Era (SURGeLLM 2026), pages 119–131, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
RSAT: Structured Attribution Makes Small Language Models Faithful Table Reasoners (Gajjar & Subramaniakuppusamy, SURGeLLM 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.surgellm-1.7.pdf