Chandan Kumar R S
2026
Team CV at SemEval-2026 Task 4: Prompting LLMs and Benchmarking Embedding Models for Narrative Story Similarity
Chandan Kumar R S | Vinay Ulli
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Chandan Kumar R S | Vinay Ulli
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
This paper describes Team CV’s systems forSemEval-2026 Task 4: Narrative Story Sim-ilarity and Narrative Representation Learn-ing (Hatzel et al., 2026). For Track A (com-parative judgment), we explore five prompt-ing strategies—zero-shot, chain-of-thought,structured feature extraction, pairwise scor-ing, and few-shot—and QLoRA fine-tuningof smaller models. For Track B (narrativeembeddings), we benchmark twelve dedicatedtext embedding models of varying dimen-sionality (384–4096) spanning open-source(E5-Large-v2, BGE, GTE, Qwen3 Embed-ding) and closed-source (OpenAI, Gemini,Mistral) families, and fine-tune Qwen3 Em-bedding 4B on task-specific triples. Few-shot prompting with Qwen-2.5 7B (64.00%)outperforms all fine-tuned variants (best57.50%) on Track A; scaling to LLaMA-3.3-70B yields 75.00%. On Track B, Ope-nAI text-embedding-3-large (3072-d) achieves the best dev accuracy (67.00%),while fine-tuning Qwen3 Embedding 4B(2560-d) on synthetic triples slightly de-creases accuracy. Our final submission—LLaMA-3.3-70B (3-shot) for Track A andtext-embedding-3-large for Track B—achieves 70.75% and 64.50%, exceeding theGPT-4o-mini and STORY-EMB baselines respec-tively.
TypeCoT at UZH Shared Task 2026: Reconstructing Argumentative Structure in UN Resolutions using Type-Informed Chain-of-Thought
Chandan Kumar R S | Vinay Babu Ulli | Jyoti Kumari | Vaibhav Singh
Proceedings of the 13th Workshop on Argument Mining and Reasoning
Chandan Kumar R S | Vinay Babu Ulli | Jyoti Kumari | Vaibhav Singh
Proceedings of the 13th Workshop on Argument Mining and Reasoning
United Nations and UNESCO resolutions encode complex collective reasoning through highly structured preambles and operative clauses. Reconstructing this implicit argumentative structure is a challenging natural language processing task. This paper describes our submission to the UZH Shared Task at the ArgMining Workshop 2026. Adhering to the strict constraint of using open-weight models with at most 8B parameters, we propose a highly efficient, modular pipeline built entirely upon the Qwen-2.5-7B-Instruct architecture. To address Subtask 1, we decouple the problem, employing a 4-bit quantized LoRA adapter via the Unsloth framework for paragraph type classification and a type-informed chain-of-thought approach for thematic tagging and relation prediction.