Knowing What’s Missing: Assessing Information Sufficiency in Question Answering

Akriti Jain, Aparna Garimella


Abstract
Determining whether a provided context contains sufficient information to answer a question is a critical challenge for building reliable question-answering systems. While simple prompting strategies have shown success on factual questions, they frequently fail on inferential ones that require reasoning beyond direct text extraction. We hypothesize that asking a model to first reason about what specific information is missing provides a more reliable, implicit signal for assessing overall sufficiency. To this end, we propose a structured Identify-then-Verify framework for robust sufficiency modeling. Our method first generates multiple hypotheses about missing information and establishes a semantic consensus. It then performs a critical verification step, forcing the model to re-examine the source text to confirm whether this information is truly absent. We evaluate our method against established baselines across diverse multi-hop and factual QA datasets. The results demonstrate that by guiding the model to justify its claims about missing information, our framework produces more accurate sufficiency judgments while clearly articulating any information gaps.
Anthology ID:
2026.findings-eacl.217
Volume:
Findings of the Association for Computational Linguistics: EACL 2026
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4163–4174
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.217/
DOI:
Bibkey:
Cite (ACL):
Akriti Jain and Aparna Garimella. 2026. Knowing What’s Missing: Assessing Information Sufficiency in Question Answering. In Findings of the Association for Computational Linguistics: EACL 2026, pages 4163–4174, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Knowing What’s Missing: Assessing Information Sufficiency in Question Answering (Jain & Garimella, Findings 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.217.pdf
Checklist:
 2026.findings-eacl.217.checklist.pdf