CASPER in the Machine: Insights into Character Variety in LLM-Generated Stories

2026-06-21

AI Summary

This study investigates the differences between stories generated by large language models (LLMs) and those authored by humans with respect to character diversity. Drawing on narrative theory, the authors propose a novel analytical framework comprising eight dimensions—such as stylization and coherence—and integrate automated classification techniques to conduct both quantitative and qualitative comparisons. The findings reveal that while LLMs approach human-level performance on certain character dimensions, they still exhibit significant gaps in diversity and depth. By systematically delineating the capabilities and limitations of LLMs in character construction, this work advances the theoretical and methodological foundations for evaluating narrative competence in artificial intelligence systems.

Abstract

As LLM-generated text is increasingly used, especially in fictional domains, we explore how much LLM-generated stories differ from human-written stories. In this work, we focus on characters. We borrow definitions from narratology to analyze eight intricate dimensions of character, such as stylization and wholeness. These dimensions consider more than just basic characteristics. They assess how characters are portrayed within their stories. After automatically inferring categories of characters within both LLM and human-written stories, we compare and contrast these two sets of stories. We consider the following overarching questions: (1) Do LLMs and human-written stories have similar characters? and (2) Do LLMs generate stories with a variety of characters? Our analysis includes research questions that focus on stories generated by popular LLMs and recently published human-written stories. We describe a number of interesting similarities, differences and key takeaways.

Problem

• LLM-generated stories
• character variety
• narratology
• human-written stories
• character portrayal

Innovation

• character variety
• large language models
• narratology
• story generation
• character analysis