zzucs at PsyDefDetect: Bridging Long-Tail Imbalance and Clinical Rubrics for DMRS Defense-Level Detection

Bin Huang, Liuyuan Su, Kaixuan Yuan, Guanghui Zhao, Shixin Zhang, Kunli Zhang


Abstract
Detecting DMRS defense levels in emotionalsupport dialogues is challenging due to severe class imbalance and fine-grained clinical distinctions between adjacent levels, issueswell documented in psychotherapy-orientedNLP surveys (Na et al., 2025). We presentzzucs for PsyDefDetect at BioNLP 2026 (Naet al., 2026a), adopting a data–supervisionco-design strategy. SCCR applies stratifiedresampling to balance support across nine defense levels. CoR–QLoRA encodes clinical rubrics, including task contracts, taxonomy definitions, and boundary cues, into staticprompts for 8B model fine-tuning. Ablationsshow SCCR improves macro-F1 by 4.9 pointsover random oversampling. Our system fromteam zzucs, submitted on CodaBench underthe display name sly_zzu with submission ID652647, achieves 0.3585 macro-F1 on the official blind-test leaderboard LB1. It ranks6th of 21 registered teams with official submissions and surpasses all published 8B baselines by 4.4 F1 points over the strongest 8Bcomparator, Ministral-8B. The code has beenreleased at https://github.com/jackssdd/zzucs_psydefdetect_code.
Anthology ID:
2026.bionlp-2.3
Volume:
Proceedings of the BioNLP 2026 (Shared Tasks)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Deepak Gupta, Dina Demner-Fushman
Venues:
BioNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
13–23
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-2.3/
DOI:
Bibkey:
Cite (ACL):
Bin Huang, Liuyuan Su, Kaixuan Yuan, Guanghui Zhao, Shixin Zhang, and Kunli Zhang. 2026. zzucs at PsyDefDetect: Bridging Long-Tail Imbalance and Clinical Rubrics for DMRS Defense-Level Detection. In Proceedings of the BioNLP 2026 (Shared Tasks), pages 13–23, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
zzucs at PsyDefDetect: Bridging Long-Tail Imbalance and Clinical Rubrics for DMRS Defense-Level Detection (Huang et al., BioNLP 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-2.3.pdf
Supplementarymaterial:
 2026.bionlp-2.3.SupplementaryMaterial.zip
Supplementarymaterial:
 2026.bionlp-2.3.SupplementaryMaterial.txt