Supervised Contrastive Fine-Tuning for Active Few-Shot Learning

Zirui Zhang, Lei Ge, Shengyu Qiao


Abstract
Active Few-Shot Learning (AFSL) is an effective paradigm for improving the performance of large language models under limited annotation budgets. To address the inefficiency of conventional fine-tuning objectives in AFSL, this paper proposes a supervised contrastive fine-tuning framework specifically designed for natural language processing (NLP) text classification tasks. By integrating Supervised Contrastive Learning (SCL) with Hard Negative Mining (HNM), the proposed framework optimizes the embedding space through an enhanced hybrid loss function, thereby improving the utilization efficiency of labeled samples. Extensive experiments on five benchmark datasets show that, under a fixed state-of-the-art (SOTA) query strategy, our method consistently outperforms baseline models in text classification performance, and exhibits strong generalizability across different backbone architectures and acquisition functions. These findings demonstrate that optimizing how to learn—through improved learning objectives—provides a complementary direction to existing query strategies in advancing AFSL.
Anthology ID:
2026.lrec-1.814
Volume:
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Stelios Piperidis, Núria Bel, Henk van den Heuvel, Nancy Ide, Simon Krek, Antonio Toral
Venue:
LREC
SIG:
Publisher:
ELRA Language Resource Association
Note:
Pages:
10365–10375
Language:
URL:
https://aclanthology.org/2026.lrec-1.814/
DOI:
10.63317/5p4u2sjsmrcm
Bibkey:
Cite (ACL):
Zirui Zhang, Lei Ge, and Shengyu Qiao. 2026. Supervised Contrastive Fine-Tuning for Active Few-Shot Learning. In Proceedings of the Fifteenth Language Resources and Evaluation Conference, pages 10365–10375, Palma de Mallorca, Spain. ELRA Language Resource Association.
Cite (Informal):
Supervised Contrastive Fine-Tuning for Active Few-Shot Learning (Zhang et al., LREC 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.lrec-1.814.pdf
External:
 https://lrec.elra.info/lrec2026-main-814