Texts or Images? A Fine-grained Analysis on the Effectiveness of Input Representations and Models for Table Question Answering

Wei Zhou, Mohsen Mesgar, Heike Adel, Annemarie Friedrich


Abstract
In table question answering (TQA), tables are encoded as either texts or images. Prior work suggests that passing images of tables to multi-modal large language models (MLLMs) performs comparably to using textual input with large language models (LLMs). However, the lack of controlled setups limits fine-grained distinctions between these approaches. In this paper, we conduct the first controlled study on the effectiveness of several combinations of table representations and model types from two perspectives: question complexity and table size. We build a new benchmark based on existing TQA datasets. In a systematic analysis of seven pairs of MLLMs and LLMs, we find that the best combination of table representation and model varies across setups. We propose FRES, a method selecting table representations dynamically, and observe a 10% average performance improvement compared to using both representations indiscriminately.
Anthology ID:
2025.findings-acl.117
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2307–2318
Language:
URL:
https://preview.aclanthology.org/transition-to-people-yaml/2025.findings-acl.117/
DOI:
10.18653/v1/2025.findings-acl.117
Bibkey:
Cite (ACL):
Wei Zhou, Mohsen Mesgar, Heike Adel, and Annemarie Friedrich. 2025. Texts or Images? A Fine-grained Analysis on the Effectiveness of Input Representations and Models for Table Question Answering. In Findings of the Association for Computational Linguistics: ACL 2025, pages 2307–2318, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Texts or Images? A Fine-grained Analysis on the Effectiveness of Input Representations and Models for Table Question Answering (Zhou et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/transition-to-people-yaml/2025.findings-acl.117.pdf