TopicGPT: A Prompt-based Topic Modeling Framework
Chau Minh Pham, Alexander Hoyle, Simeng Sun, Philip Resnik, Mohit Iyyer
TL;DR
TopicGPT introduces a prompt-driven framework that leverages large language models to generate and assign topics from text corpora, producing human-friendly topics with labels, descriptions, and grounded quotes. By combining iterative topic generation with refinement and a self-correcting assignment module, TopicGPT achieves higher alignment with ground-truth topics than traditional baselines like LDA, BERTopic, and SeededLDA across Wiki and Bills datasets. The approach emphasizes interpretability, adaptability, and verifiability, enabling multi-label document-topic associations and reducing misaligned topics through refinement. Robust across prompts and samples, the method offers a practical, human-centered alternative for automated content analysis, while acknowledging current limitations around closed-source model dependence, cost, context limits, and multilinguality.
Abstract
Topic modeling is a well-established technique for exploring text corpora. Conventional topic models (e.g., LDA) represent topics as bags of words that often require "reading the tea leaves" to interpret; additionally, they offer users minimal control over the formatting and specificity of resulting topics. To tackle these issues, we introduce TopicGPT, a prompt-based framework that uses large language models (LLMs) to uncover latent topics in a text collection. TopicGPT produces topics that align better with human categorizations compared to competing methods: it achieves a harmonic mean purity of 0.74 against human-annotated Wikipedia topics compared to 0.64 for the strongest baseline. Its topics are also interpretable, dispensing with ambiguous bags of words in favor of topics with natural language labels and associated free-form descriptions. Moreover, the framework is highly adaptable, allowing users to specify constraints and modify topics without the need for model retraining. By streamlining access to high-quality and interpretable topics, TopicGPT represents a compelling, human-centered approach to topic modeling.
