CreativeInstruct: Scalably Teaching LLMs to Balance Quality, Creativity, and Diversity

2026-08-07Computation and Language

Computation and LanguageArtificial Intelligence
AI summary

The authors found that improving large language models often makes their responses less creative, which is a problem for tasks needing creativity like story writing. To fix this, they created CreativeInstruct, a method that helps models generate more creative and varied outputs by adding special markers that encourage creativity. They also developed a new way to measure creativity using structural changes in stories. Their method keeps quality high while boosting creativity, confirmed by both automatic tests and human ratings. Additionally, their creative models improved performance in reinforcement learning tasks compared to standard models.

large language modelspost-traininginstruction tuningcreativitynarrative generationgraph edit distancereinforcement learningGRPOquality-diversity tradeoff
Authors
Ananya Sahu, Mohit Bansal, Elias Stengel-Eskin
Abstract
While post-training improves the capabilities of large language models (LLMs), it generally lowers their output diversity and creativity, negatively impacting tasks that explicitly require creativity (e.g., story generation) as well as those that require it implicitly, e.g., reinforcement learning (RL). We instead propose CreativeInstruct, a scalable instruction-tuning method that teaches LLMs to balance creative, base-model-like generations with the quality of post-trained models, by learning to inject special [StartCreativity] spans that bias generation toward creativity. Furthermore, we introduce a structural diversity metric based on graph edit distance, which captures narrative level variation missed by purely lexical and semantic metrics. On narrative generation, CreativeInstruct matches or exceeds the diversity of both multi-model baselines and distilled variants of their outputs, without sacrificing quality or requiring multiple models at inference time. These results are mirrored in our human evaluation, where we find that annotators rate CreativeInstruct generations as more creative than the post-trained LLMs' generations in 70.3% of cases. We also show the benefits of creative models as a substrate for RL: GRPO applied to a CreativeInstruct checkpoint improves by ~4% on AMC and ~5% points on MATH over the same training applied to the post-trained checkpoint.