An Empirical Investigation of Robustness in Large Language Models under Tabular Distortions
Avik Dutta, Harshit Nigam, Hosein Hasanbeig, Arjun Radhakrishna, Sumit Gulwani
TL;DR
This work assesses how large language models handle distorted tabular data in table question answering. It introduces a small, expert-curated dataset with semantic and structural distortions to quantify robustness across model families, input modalities, and tool usage. The findings show that LLMs lack inherent distortion awareness, with structural distortions causing larger errors and vertical misalignments being particularly challenging; prompting with distortion awareness improves performance but is not consistently reliable. The study highlights a need for autonomous table realignment and repair capabilities in future models, beyond reliance on explicit prompts or pre-processing, to enable robust real-world TQA. $R_{ ext{bst}} = rac{ ext{Dist}}{ ext{Can}}$ is used to measure robustness, and results indicate significant gaps even for SoTA models like GPT-5.2 under distortion.
Abstract
We investigate how large language models (LLMs) fail when tabular data in an otherwise canonical representation is subjected to semantic and structural distortions. Our findings reveal that LLMs lack an inherent ability to detect and correct subtle distortions in table representations. Only when provided with an explicit prior, via a system prompt, do models partially adjust their reasoning strategies and correct some distortions, though not consistently or completely. To study this phenomenon, we introduce a small, expert-curated dataset that explicitly evaluates LLMs on table question answering (TQA) tasks requiring an additional error-correction step prior to analysis. Our results reveal systematic differences in how LLMs ingest and interpret tabular information under distortion, with even SoTA models such as GPT-5.2 model exhibiting a drop of minimum 22% accuracy under distortion. These findings raise important questions for future research, particularly regarding when and how models should autonomously decide to realign tabular inputs, analogous to human behavior, without relying on explicit prompts or tabular data pre-processing.
