Penetrating Linguistic Disguises: A Slang-aware Label-Aligned Framework for Fine-Grained Toxicity Extraction in Chinese Hate Speech Detection

摘要

Flexible word boundaries and linguistic obfuscation, particularly slang, challenge precise span-level hate speech detection in Chinese. While benchmarks such as STATE ToxiCN demand the exact extraction of Target-Argument-Hateful-Group quadruples, generative Large Language Models (LLMs) often fail strict boundary constraints. In contrast, discriminative 2D Grid Tagging methods frequently encounter label collisions. To resolve these problems, this study presents a Slang-aware Label-Aligned Framework. A Structural-Semantic Lexicon Fusion (SSLF) module reduces ambiguity by mapping obscure slang to explicit hate semantics. Additionally, the proposed Label-Disentangled Volumetric Tagging (LDVT) projects token interactions into a volumetric space. LDVT uses task-specific branches and dedicated label channels to structurally mitigate feature interference. This approach removes label collisions without heuristic post-processing. Empirical outcomes on STATE ToxiCN indicate a Hard-F1 of 30.09%. This performance is 5.82% higher than the best fine-tuned LLM baseline and confirms the method is effective for exact-match extraction.