SoloSemantics at SemEval-2026 Task 4: Triplet-Tuned MPNet for Story Similarity

Steven Au


Abstract
This paper describes Team SoloSemantics’ submissions to SemEval-2026 Task 4: Narrative Story Similarity and Narrative Representation Learning. We began with lightweight neuro-symbolic knowledge-graph baselines, but a triplet-tuned MPNet bi-encoder produced stronger semantic separation in our experiments. We adopted a shared dense encoder family across both tracks and kept the KG and fusion variants as diagnostic baselines. Team SoloSemantics ranked 22nd on Track A and 9th on Track B. Our reproducibility audit further shows that the KG branch was often too sparse on short summaries to represent abstract narrative relations reliably under the current extraction pipeline.
Anthology ID:
2026.semeval-1.201
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:
1547–1553
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.201/
DOI:
Bibkey:
Cite (ACL):
Steven Au. 2026. SoloSemantics at SemEval-2026 Task 4: Triplet-Tuned MPNet for Story Similarity. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 1547–1553, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
SoloSemantics at SemEval-2026 Task 4: Triplet-Tuned MPNet for Story Similarity (Au, SemEval 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.201.pdf
Supplementarymaterial:
 2026.semeval-1.201.SupplementaryMaterial.zip