UNCC at MedGenVidQA 2026: Structured Temporal Grounding for Medical Video Question Answering

Hilmi Demirhan, Wlodek Zadrozny


Abstract
MedGenVidQA 2026 Task C evaluates visualanswer localization in medical videos. Thesystem receives a video and a question, then returns the start and end time of the visual answer.Our framework used timestamped automaticspeech recognition (ASR) as a proposal sourcerather than as a final boundary label. The framework generated transcript tables, phase maps,lexical and dense candidate windows, schemaconstrained ranking inputs, selective key-framechecks, and a deterministic validation pass forthe final JSON file. The ranker selected amongbounded candidate intervals instead of generating arbitrary timestamps over a full transcript.Each output can be traced to segment identifiers, candidate source families, selected anchors, phase labels, and validation flags. Ourbest run ranked fifth among six participant systems, with 62.50 IoU@0.3, 36.25 IoU@0.5,22.50 IoU@0.7, and 42.57 mIoU. The threshold pattern suggests that coarse temporal retrieval was more reliable than strict start-endlocalization.
Anthology ID:
2026.bionlp-2.35
Volume:
Proceedings of the BioNLP 2026 (Shared Tasks)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Deepak Gupta, Dina Demner-Fushman
Venues:
BioNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
262–269
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-2.35/
DOI:
Bibkey:
Cite (ACL):
Hilmi Demirhan and Wlodek Zadrozny. 2026. UNCC at MedGenVidQA 2026: Structured Temporal Grounding for Medical Video Question Answering. In Proceedings of the BioNLP 2026 (Shared Tasks), pages 262–269, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
UNCC at MedGenVidQA 2026: Structured Temporal Grounding for Medical Video Question Answering (Demirhan & Zadrozny, BioNLP 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-2.35.pdf
Supplementarymaterial:
 2026.bionlp-2.35.SupplementaryMaterial.txt