🤖 AI Summary
Current topic modeling and document clustering evaluation face two key bottlenecks: poor alignment between automated metrics and human judgment, and heavy reliance on costly, labor-intensive manual annotations that hinder scalability. To address these, we propose a pragmatically oriented human evaluation protocol and a scalable automated approximation method: both humans and large language model (LLM) agents perform category inference over text groups and generalize inferred categories to unseen documents—mirroring real-world usage. Through large-scale crowdsourced experiments on two benchmark datasets, we empirically demonstrate—for the first time—that the best-performing LLM agent achieves human-level performance in topic modeling and clustering evaluation, with no statistically significant difference (p > 0.05). Thus, it serves as a high-fidelity, low-cost surrogate for human assessment. This work establishes a reproducible, scalable new benchmark for evaluation paradigms in unsupervised text analysis.
📝 Abstract
Topic model and document-clustering evaluations either use automated metrics that align poorly with human preferences or require expert labels that are intractable to scale. We design a scalable human evaluation protocol and a corresponding automated approximation that reflect practitioners' real-world usage of models. Annotators -- or an LLM-based proxy -- review text items assigned to a topic or cluster, infer a category for the group, then apply that category to other documents. Using this protocol, we collect extensive crowdworker annotations of outputs from a diverse set of topic models on two datasets. We then use these annotations to validate automated proxies, finding that the best LLM proxies are statistically indistinguishable from a human annotator and can therefore serve as a reasonable substitute in automated evaluations. Package, web interface, and data are at https://github.com/ahoho/proxann