Open Ko-LLM Leaderboard: Evaluating Large Language Models in Korean with Ko-H5 Benchmark
Chanjun Park, Hyeonwoo Kim, Dahyun Kim, Seonghwan Cho, Sanghoon Kim, Sukyung Lee, Yungi Kim, Hwalsuk Lee
TL;DR
The paper introduces the Open Ko-LLM Leaderboard and Ko-H5 Benchmark to standardize and extend Korean LLM evaluation, aligning with the English-led Open LLM Leaderboard and using private test sets to mitigate data leakage. It details a rigorous curation pipeline, including translation and domain-aware review, and demonstrates that Ko-H5 adds linguistic diversity through Ko-CommonGen v2 while maintaining low overlap with training data. Temporal and size-type analyses reveal stepwise performance gains, a strong link between pretraining and instruction-tuning, and task-specific saturation dynamics, motivating expansion beyond fixed benchmarks. The work emphasizes community involvement and evolving benchmark practices to better reflect real-world use cases and linguistic diversity in Korean NLP applications.
Abstract
This paper introduces the Open Ko-LLM Leaderboard and the Ko-H5 Benchmark as vital tools for evaluating Large Language Models (LLMs) in Korean. Incorporating private test sets while mirroring the English Open LLM Leaderboard, we establish a robust evaluation framework that has been well integrated in the Korean LLM community. We perform data leakage analysis that shows the benefit of private test sets along with a correlation study within the Ko-H5 benchmark and temporal analyses of the Ko-H5 score. Moreover, we present empirical support for the need to expand beyond set benchmarks. We hope the Open Ko-LLM Leaderboard sets precedent for expanding LLM evaluation to foster more linguistic diversity.
