PortNLP at CRAC 2026: QLoRA Fine-Tuning with Bounded Entity Registry for Multilingual Coreference Resolution

Amber Shore, Russell Scheinberg, Malini Nagasundaram, Ameeta Agrawal


Abstract
We describe PortNLP’s submission to the CRAC 2026 Shared Task on Multilingual Coreference Resolution (LLM track). Our system fine-tunes Qwen 3 14B with QLoRA on CorefUD 1.4 gold annotations across 27 corpora spanning 19 languages. Documents are processed in 500-700 character chunks with a bounded rolling context consisting of 500 characters of recent annotated text and a scored entity registry that tracks up to 30 active entities via a frequency-times-recency decay formula. We employ data augmentation and language-aware sampling strategies to handle typological and data-size diversity. Our system achieves 68.69 CoNLL F1 averaged across all 27 test corpora. We additionally present probing experiments on the LoRA adapter’s internal representations, finding that coreference signal is concentrated in attention value projections rather than MLP modules, with the strongest readout at the earliest transformer layer.
Anthology ID:
2026.codi-1.25
Volume:
Proceedings of the 2nd Joint Workshop on Computational Approaches to Discourse, Context and Document-Level Inferences and Computational Models of Reference, Anaphora and Coreference (CODI-CRAC 2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Chloé Braud, Christian Hardmeier, Maciej Ogrodniczuk, Sharid Loaiciga, Amir Zeldes, Michal Novák, Chuyuan Li, Michael Strube, Junyi Jessy Li
Venues:
CODI | CRAC | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
193–198
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.codi-1.25/
DOI:
Bibkey:
Cite (ACL):
Amber Shore, Russell Scheinberg, Malini Nagasundaram, and Ameeta Agrawal. 2026. PortNLP at CRAC 2026: QLoRA Fine-Tuning with Bounded Entity Registry for Multilingual Coreference Resolution. In Proceedings of the 2nd Joint Workshop on Computational Approaches to Discourse, Context and Document-Level Inferences and Computational Models of Reference, Anaphora and Coreference (CODI-CRAC 2026), pages 193–198, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
PortNLP at CRAC 2026: QLoRA Fine-Tuning with Bounded Entity Registry for Multilingual Coreference Resolution (Shore et al., CODI-CRAC 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.codi-1.25.pdf
Supplementarymaterial:
 2026.codi-1.25.SupplementaryMaterial.zip