CUS-QA: Local-Knowledge-Oriented Open-Ended Question Answering Dataset

Jindrich Libovický, Jindrich Helcl, Andrei-Alexandru Manea, Gianluca Vico


Abstract
We introduce CUS-QA, a benchmark for evaluation of open-ended regional question answering that encompasses both textual and visual modalities. We also provide strong baselines using state-of-the-art large language models (LLMs). Our dataset consists of manually curated questions and answers grounded in Wikipedia, created by native speakers from Czechia, Slovakia, and Ukraine, with accompanying English translations. It includes both purely textual questions and those requiring visual understanding. We evaluate state-of-the-art LLMs through prompting and add human judgments of answer correctness. Using these human evaluations, we analyze the reliability of existing automatic evaluation metrics. Our baseline results show that even the best open-weight LLMs achieve only over 40% accuracy on textual questions and below 30% on visual questions. LLM-based evaluation metrics show strong correlation with human judgment, while traditional string-overlap metrics perform surprisingly well due to the prevalence of named entities in answers.
Anthology ID:
2026.tacl-1.67
Volume:
Transactions of the Association for Computational Linguistics, Volume 14
Month:
Year:
2026
Address:
Cambridge, MA
Venue:
TACL
SIG:
Publisher:
MIT Press
Note:
Pages:
1482–1509
Language:
URL:
https://aclanthology.org/2026.tacl-1.67/
DOI:
10.1162/tacl.a.737
Bibkey:
Cite (ACL):
Jindrich Libovický, Jindrich Helcl, Andrei-Alexandru Manea, and Gianluca Vico. 2026. CUS-QA: Local-Knowledge-Oriented Open-Ended Question Answering Dataset. Transactions of the Association for Computational Linguistics, 14:1482–1509.
Cite (Informal):
CUS-QA: Local-Knowledge-Oriented Open-Ended Question Answering Dataset (Libovický et al., TACL 2026)
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PDF:
https://aclanthology.org/2026.tacl-1.67.pdf