VIRA-Bench: Diagnosing Pedagogical Contingency Understanding in Online Tutoring Videos

Weihang Wang, Hansu Gu, Guanming Liu, Peng Zhang, Ning Gu, Tun Lu


Abstract
Understanding online tutoring requires more than recognizing isolated events. A model must connect what a teacher says or does to how the learner responds and how the teacher subsequently adapts. Existing video benchmarks emphasize event and temporal understanding, while educational-dialogue benchmarks are largely transcript-based, leaving this interactional contingency underexplored. We introduce VIRA-Bench, a diagnostic benchmark for short-horizon pedagogical contingency in one-to-one tutoring videos. Grounded in the Initiation–Response–Follow-up structure and contingent teaching theory, VIRA-Bench contains 1,005 clips and 1,322 multiple-choice questions organized into three layers: Observable Evidence Grounding, Interaction Contingency Reasoning, and Support-Response Modeling. Items are built through researcher-led evidence auditing and expert verification to keep questions tied to observable interaction evidence. Across 11 multimodal large language models, the best model reaches 61.3% accuracy, compared with 91.0% on a stratified human subset, with interaction contingency reasoning emerging as the most consistent weakness. Controlled evidence interventions reveal distinct dependencies across layers. Removing video hurts observable grounding most, while disrupting interaction order hurts contingency reasoning most. Additional controls show that this distinction survives free-response evaluation and cannot be explained by question-option shortcuts or video–transcript misalignment. By separating visual grounding from order-sensitive interaction reasoning, VIRA-Bench exposes diagnostic differences that aggregate video-QA scores obscure.
Anthology ID:
2026.emnlp-main.1245
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
28368–28388
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1245/
DOI:
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Cite (ACL):
Weihang Wang, Hansu Gu, Guanming Liu, Peng Zhang, Ning Gu, and Tun Lu. 2026. VIRA-Bench: Diagnosing Pedagogical Contingency Understanding in Online Tutoring Videos. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 28368–28388, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
VIRA-Bench: Diagnosing Pedagogical Contingency Understanding in Online Tutoring Videos (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1245.pdf