ProbeTQA: Verifiable Table Question Answering via Multi-Round Executable Probing

Yan Liang, Huimin Ren, Xindi Zhang, Hongsheng Xin, Wenbin Huo, Yanan Guo, Jinpeng Zheng, Kaike Zhang, Kun Zhan, Jiani Hu


Abstract
Enabling Large Language Models (LLMs) to perform tool-free Table Question Answering (TableQA) presents two critical challenges: "question-first" data synthesis often introduces logical hallucinations, while standard reinforcement learning (RL) suffers from sparse rewards over long reasoning chains. We propose ProbeTQA, a unified framework that couples execution-verified data construction with process-supervised RL. To mitigate synthesis hallucinations, ProbeTQA adopts an answer-first executable probing paradigm, in which an agent performs multi-round exploratory programming over real tables so that every synthesized instance is grounded in a verifiable witness program. To address reward sparsity, we convert verified code trajectories into natural-language reasoning traces and derive execution-grounded process rubrics directly from runtime states, providing reliable dense supervision. Using these rubrics, we optimize the model with Group Relative Policy Optimization (GRPO) under a Two-Stage Reward Curriculum, thereby internalizing complex tool-use reasoning into the model parameters. Experiments show that our 8B model achieves state-of-the-art tool-free performance on challenging benchmarks, attaining 65.8% accuracy on TableBench and outperforming GPT-5.4 and DeepSeek-v3.2 by 13.4 and 6.8 percentage points, respectively.
Anthology ID:
2026.emnlp-main.900
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
20715–20741
Language:
URL:
https://aclanthology.org/2026.emnlp-main.900/
DOI:
Bibkey:
Cite (ACL):
Yan Liang, Huimin Ren, Xindi Zhang, Hongsheng Xin, Wenbin Huo, Yanan Guo, Jinpeng Zheng, Kaike Zhang, Kun Zhan, and Jiani Hu. 2026. ProbeTQA: Verifiable Table Question Answering via Multi-Round Executable Probing. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 20715–20741, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ProbeTQA: Verifiable Table Question Answering via Multi-Round Executable Probing (Liang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.900.pdf