
Embedding-free framework enables private topic discovery in LLM conversations
The authors introduce CALLIOPE, a framework that discovers topic hierarchies from large text corpora (e.g., LLM conversations) while supporting differential privacy. Unlike prior approaches that rely on clustering vector embeddings, CALLIOPE operates entirely in the text domain by leveraging LLMs to abstract documents and recursively build taxonomies. The authors report that this approach yields better utility than embedding-based methods, especially under tight privacy budgets.














































