KoSimpleQA: A Korean Factuality Benchmark with an Analysis of Reasoning LLMs
Donghyeon Ko, Yeguk Jin, Kyubyung Chae, Byungwook Lee, Chansong Jo, Sookyo In, Jaehong Lee, Taesup Kim, Donghyun Kwak
TL;DR
KoSimpleQA fills a gap in factuality benchmarking by focusing on Korean cultural knowledge with 1,000 unambiguous questions collected under strict temporal and difficulty constraints. The authors evaluate a broad set of open-source LLMs that support Korean and analyze how reasoning-enabled models behave on factual QA, finding that even strong models struggle (max ~33.7% accuracy) and that cultural grounding affects model rankings relative to English benchmarks. A key contribution is the demonstration that reasoning can both reveal latent knowledge and increase abstention when uncertain, highlighting nuanced dynamics in factual QA. The dataset and findings provide a foundation for culturally grounded, factually reliable language models and point to future work in extending evaluation to longer, more complex outputs.
Abstract
We present $\textbf{Korean SimpleQA (KoSimpleQA)}$, a benchmark for evaluating factuality in large language models (LLMs) with a focus on Korean cultural knowledge. KoSimpleQA is designed to be challenging yet easy to grade, consisting of 1,000 short, fact-seeking questions with unambiguous answers. We conduct a comprehensive evaluation across a diverse set of open-source LLMs of varying sizes that support Korean, and find that even the strongest model generates correct answer only 33.7% of the time, underscoring the challenging nature of KoSimpleQA. Notably, performance rankings on KoSimpleQA differ substantially from those on the English SimpleQA, highlighting the unique value of our dataset. Furthermore, our analysis of reasoning LLMs shows that engaging reasoning capabilities in the factual QA task can both help models better elicit their latent knowledge and improve their ability to abstain when uncertain. KoSimpleQA can be found at https://anonymous.4open.science/r/KoSimpleQA-62EB.
