Barom Kang
2026
E-star 12B: Reliable Rubric-Following and Domain-Adaptive SLM Evaluator for Korean Industrial Settings
Yonghoon Kwon | Heondeuk Lee | Barom Kang
Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM)
Yonghoon Kwon | Heondeuk Lee | Barom Kang
Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM)
Automatic evaluation in industrial settings requires models to interpret and apply natural language rubrics reliably under language and domain shift. This challenge is compounded when reference answers are unavailable and proprietary models cannot be deployed due to data-governance constraints. We present E-Star-12B, a 12B-parameter evaluator for Korean industrial environments that jointly addresses rubric following and domain adaptation. Our approach combines a structured evaluation format—feedback, highlight, and decision—with a 6K high-confidence training set via multi-stage consensus-based filtering. We introduce two benchmarks: Ko Feedback Bench for rubric-following evaluation under Korean language transfer, and RAG Quality Bench for domain-specific evaluation in financial and legal settings. E-Star-12B achieves the strongest rubric alignment among small language models on Ko Feedback Bench, improving Pearson correlation by +0.173 over its base model. On RAG Quality Bench, the domain-adapted variant approaches frontier-model performance with more stable adaptation than general instruct models. Strong rubric-following capability serves as a reliable scaffold for subsequent domain adaptation.