This August 2025 paper introduces NOVELTYBENCH, a new benchmark designed to evaluate how well large language models (LLMs) generate diverse and high-quality outputs, addressing the problem of "mode collapse" where models produce repetitive responses. The research found that current state-of-the-art LLMs consistently generate less diversity than human writers, with larger models often exhibiting even lower diversity than their smaller counterparts. The benchmark uses a unique approach to measure functional equivalence between generations, ensuring that diversity is meaningful to users. While certain prompting strategies, like in-context regeneration, can enhance diversity, the study suggests that this capability is not inherent in the models themselves, highlighting the need for new training and evaluation paradigms that prioritize both diversity and quality in LLM development.

Source:

https://arxiv.org/pdf/2504.05228