TVKS@MMLow 2026: Factorized Stance × Target Classification of Tamil Political Memes with an Axis-Wise Multimodal Ensemble

Kevin selva K, Thilagavathy R


Abstract
We describe the TVKS submission to the MMLow 2026 shared task on multilevel classification of Tamil political memes, which asks systems to predict a stance label (Level 1: Support/Praise vs. Troll/Oppose) and a four-way target label (Level 2) that combines stance with a Person/Party distinction. We factorize the Level 2 label into two binary axes—stance and person/party target—reconstructing Level 2 as their product rather than predicting four classes directly. A flat four-way head drives the rarest class (Troll/Oppose Against Party) to an F1 of 0.000; factorization recovers a non-degenerate prediction over all four classes. We also fix a calibration failure caused by stacking a class-balanced sampler with a class-weighted loss, and combine two multimodal models (MuRIL + ViT and MuRIL + ResNet-50) in an axis-wise ensemble that routes each binary axis to its stronger model. Our system reaches a macro-F1 of 0.8594 on Level 1 and 0.5926 on Level 2 (mean 0.7260), ranking second of seven teams. An error analysis attributes 77% of Level 2 errors to the person/party axis, where architecturally distinct visual encoders converge to the same ceiling—evidence that the residual gap is dataset ambiguity rather than a modelling deficiency.
Anthology ID:
2026.mmlow-main.7
Volume:
Proceedings of the Fifth Workshop on Multimodal Machine Learning in Low-resource Languages
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Rahul Ponnusamy, Prasanna Kumar Kumaresan, Saranya Rajiakodi, Premjith B, Shunmuga Priya MC, Abirami Murugappan, Jyothish Lal G, Sowmya V, Bharathi Raja Chakravarthi
Venues:
MMLow | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
70–75
Language:
URL:
https://aclanthology.org/2026.mmlow-main.7/
DOI:
Bibkey:
Cite (ACL):
Kevin selva K and Thilagavathy R. 2026. TVKS@MMLow 2026: Factorized Stance × Target Classification of Tamil Political Memes with an Axis-Wise Multimodal Ensemble. In Proceedings of the Fifth Workshop on Multimodal Machine Learning in Low-resource Languages, pages 70–75, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
TVKS@MMLow 2026: Factorized Stance × Target Classification of Tamil Political Memes with an Axis-Wise Multimodal Ensemble (K & R, MMLow 2026)
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PDF:
https://aclanthology.org/2026.mmlow-main.7.pdf