ACSS-PSL at #SMM4H-HeaRD 2026: An LLM-Driven Autoresearch Loop for Opioid-Impact NER

Olivier Caron, Bruno Chaves Ferreira, Christophe Benavent


Abstract
We apply an LLM-driven autoresearch protocol to Task 7 of #SMM4H-HeaRD 2026, which requires extracting ClinicalImpacts and SocialImpacts spans from Reddit posts about non-medical opioid use. A coding agent iteratively proposes a hypothesis, modifies the training configuration, and evaluates against the held-out validation set. Across 79 runs, only 9 improved strict F1, indicating a narrow viable search space on this small dataset (842 training examples). The submitted ensemble combines DeBERTa-large, MC Dropout blending, and a constrained multi-LLM consensus layer, reaching 0.46 strict and 0.52 relaxed F1 on test, though single-seed evaluation limits the reliability of run-level comparisons. The run log provides a reproducible case study of autonomous experimentation, including failure modes and guardrails for small-data NER.
Anthology ID:
2026.smm4h-1.39
Volume:
Proceedings of the 11th Social Media Mining for Health Research and Applications (SMM4H-HeaRD 2026) Workshop and Shared Tasks
Month:
July
Year:
2026
Address:
San Diego, United States
Editors:
Guillermo Lopez-Garcia, Graciela Gonzalez-Hernandez
Venues:
SMM4H | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
240–245
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.smm4h-1.39/
DOI:
Bibkey:
Cite (ACL):
Olivier Caron, Bruno Chaves Ferreira, and Christophe Benavent. 2026. ACSS-PSL at #SMM4H-HeaRD 2026: An LLM-Driven Autoresearch Loop for Opioid-Impact NER. In Proceedings of the 11th Social Media Mining for Health Research and Applications (SMM4H-HeaRD 2026) Workshop and Shared Tasks, pages 240–245, San Diego, United States. Association for Computational Linguistics.
Cite (Informal):
ACSS-PSL at #SMM4H-HeaRD 2026: An LLM-Driven Autoresearch Loop for Opioid-Impact NER (Caron et al., SMM4H 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.smm4h-1.39.pdf