In this study, we aim to propose automated evaluation methods of LLMs that approximate human judgment by exploring and comparing two distinct approaches: (1) LLM-based scoring, which utilizes GPT models with prompt engineering, and (2) feature-based machine learning, using transformer-based metrics such as BERTScore, semantic similarity, and keyword coverage. As part of this research, we participated in the NTCIR-18 Automatic Evaluation of LLMs (AEOLLM) task. We submitted the results of the test data set and the reserved data set to NTCIR-18 and analyzed the results obtained. The results show that GPT-4o Mini (with the updated prompt) achieved the highest performance, while the feature-based approach performed competitively, surpassing GPT-3.5 Turbo and showing a small gap with GPT-4o Mini. LLM-based methods offered scalability but lacked explainability, whereas feature-based approaches provided better interpretability but required extensive tuning, highlighting the trade-offs between the two strategies. Throughout the analysis, We expect that the findings of our work will provide insights into the understanding of human judgment and automated evaluation of LLMs.
Kim et al. (Fri,) studied this question.