Distributional Stabilization for Zero-Shot Relation Extraction

Yongxin Liu, Huaping Zhang, Qiuchi Li, Chunxiao Gao, Haocheng Lv, Yan Ruohao, Baohua Zhang, Lei Li


Abstract
Joint-encoding zero-shot relation extraction classifies all candidate relation labels in a single Transformer forward pass, achieving strong accuracy and high throughput. However, under a controlled full-vocabulary diagnostic, two distributional pathologies surface: unnormalized dot-product scoring causes recall collapse, with certain types receiving zero predictions, while the per-instance BCE loss leaves gold and negative scores entangled beyond any reliable threshold—confidence ambiguity. We propose SCAR, which keeps the baseline pathway intact and stabilizes both distributions via two auxiliary branches: a gradient-isolated coarse-to-fine cascade with Z-score normalization that restores cross-relation comparability, and a training-only contrastive alignment module that separates gold from negative scores. On Wiki-ZSL (m=15), SCAR raises Macro F1 from 75.9% to 83.0% and cuts zero-recall types from 35 to 1, suggesting that small-pool ZSRE protocols can obscure failure modes critical to large-vocabulary deployment.
Anthology ID:
2026.emnlp-main.1276
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
29095–29111
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1276/
DOI:
Bibkey:
Cite (ACL):
Yongxin Liu, Huaping Zhang, Qiuchi Li, Chunxiao Gao, Haocheng Lv, Yan Ruohao, Baohua Zhang, and Lei Li. 2026. Distributional Stabilization for Zero-Shot Relation Extraction. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 29095–29111, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Distributional Stabilization for Zero-Shot Relation Extraction (Liu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1276.pdf