When and What to Ask: AskBench and Rubric-Guided RLVR for LLM Clarification

Jiale Zhao, Ke Fang, Lu Cheng


Abstract
Large language models (LLMs) often respond even when prompts omit critical details or include misleading information, leading to hallucinations or reinforced misconceptions. We study how to evaluate and improve LLMs’ ability to decide when and what to ask for clarification without sacrificing task performance. We introduce AskBench, an interactive benchmark that converts standard QA pairs into multi-turn interactions with explicit checkpoints. A unified judge loop evaluates final answers and simulates user responses as needed. AskBench covers two settings: AskMind, with intent-deficient queries requiring clarification, and AskOverconfidence, with queries containing false premises that must be identified and corrected. We further propose rubric-guided reinforcement learning with verifier-based rewards (RLVR), which uses structured rubrics to encourage targeted clarification. Experiments show consistent improvements in accuracy, rubric adherence, and interaction efficiency, with strong generalization to unseen domains.
Anthology ID:
2026.findings-acl.845
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
17120–17140
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.845/
DOI:
Bibkey:
Cite (ACL):
Jiale Zhao, Ke Fang, and Lu Cheng. 2026. When and What to Ask: AskBench and Rubric-Guided RLVR for LLM Clarification. In Findings of the Association for Computational Linguistics: ACL 2026, pages 17120–17140, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
When and What to Ask: AskBench and Rubric-Guided RLVR for LLM Clarification (Zhao et al., Findings 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.845.pdf
Checklist:
 2026.findings-acl.845.checklist.pdf