LIAAD INESCTEC at SemEval-2026 Task 4: Unsupervised Narrative Similarity via Discourse Representation Structures and Sentence Embeddings

Evelin Amorim, Alípio Jorge, Purificação Silvano


Abstract
In this paper, we describe an unsupervised approach using Discourse Representation Structures (DRS) for the SemEval-2026 Task 4. This task was Narrative Similarity and was formulated in two different tracks. Our team only developed a solution for track A, where the input is composed of a triplet: an anchor story, a story A, and a story B. The output in this formulation is to predict which story, A or B, is more similar to the anchor story. Our approach parsed each story and transformed in a DRS format,then we leveraged its structure and extracted features, performing ablation experiments inthe development dataset. Our strategy achieved 0.5975 accuracy in the official blind test set.
Anthology ID:
2026.semeval-1.277
Volume:
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Ekaterina Kochmar, Debanjan Ghosh, Kai North, Mamoru Komachi
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2193–2199
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.277/
DOI:
Bibkey:
Cite (ACL):
Evelin Amorim, Alípio Jorge, and Purificação Silvano. 2026. LIAAD INESCTEC at SemEval-2026 Task 4: Unsupervised Narrative Similarity via Discourse Representation Structures and Sentence Embeddings. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 2193–2199, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
LIAAD INESCTEC at SemEval-2026 Task 4: Unsupervised Narrative Similarity via Discourse Representation Structures and Sentence Embeddings (Amorim et al., SemEval 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.277.pdf