EvoPool: Evolutionary Programmatic Annotation for Label-Efficient Specialized Supervision

Tianyi Xu, Yaolun Zhang, Xuan Ouyang, Huazheng Wang


Abstract
Large language models excel at general tasks but underperform smaller supervised models in specialized, high-stakes domains where training labels are costly. We address this regime with EvoPool, an evolutionary multi-agent framework inspired by Darwinian evolution. Three specialized agents iteratively propose executable annotator code, a small validation set provides a fitness signal, and a deterministic gate keeps only annotators that pass viability, diversity, and marginal-contribution checks across generations. Pool votes are mapped to soft training labels by EvoAgg, a text-aware aggregator combining semantic features with annotator-vote features. The authored pool runs at near-zero per-example cost and is 4500 to 31000× faster than LLM annotation on 100K examples. Across 7 out of 8 LLM-weak specialized and complex tasks spanning biomedical relation extraction, legal-clause classification, complex reasoning, and dense multi-label biomedical classification, EvoPool beats the strongest LLM annotation baseline by an average +0.132 macro-F1, peaking at +0.275 on ChemProt and +0.268 on PubMed. Code is available at: https://github.com/tianyi0216/EvoPool.
Anthology ID:
2026.findings-emnlp.743
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
15617–15656
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.743/
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Bibkey:
Cite (ACL):
Tianyi Xu, Yaolun Zhang, Xuan Ouyang, and Huazheng Wang. 2026. EvoPool: Evolutionary Programmatic Annotation for Label-Efficient Specialized Supervision. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 15617–15656, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
EvoPool: Evolutionary Programmatic Annotation for Label-Efficient Specialized Supervision (Xu et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.743.pdf