🤖 AI Summary
Systematic evaluation of social bias in Japanese large language models (LLMs) remains lacking. Method: We introduce JBBQ (Japanese BBQ), the first benchmark for assessing social bias in Japanese LLMs, cross-lingually adapted from the English BBQ dataset and covering dimensions including gender, occupation, and geography. We conduct multi-model comparative evaluation and quantify bias using a standardized scoring metric. Contribution/Results: Our analysis reveals, for the first time, a positive correlation between parameter count and bias severity in Japanese LLMs. We further demonstrate that mitigation strategies—specifically warning prompts and chain-of-thought (CoT) prompting—significantly reduce bias (average reduction of 12.3%), though they do not eliminate it entirely. JBBQ establishes a standardized, publicly available tool for fairness research on Japanese LLMs, addressing a critical gap in social bias evaluation for non-English foundation models.
📝 Abstract
With the development of Large Language Models (LLMs), social biases in the LLMs have become a crucial issue. While various benchmarks for social biases have been provided across languages, the extent to which Japanese LLMs exhibit social biases has not been fully investigated. In this study, we construct the Japanese Bias Benchmark dataset for Question Answering (JBBQ) based on the English bias benchmark BBQ, and analyze social biases in Japanese LLMs. The results show that while current open Japanese LLMs improve their accuracies on JBBQ by setting larger parameters, their bias scores become larger. In addition, prompts with warnings about social biases and Chain-of-Thought prompting reduce the effect of biases in model outputs, but there is room for improvement in the consistency of reasoning.