LangLasso: Interactive Cluster Descriptions through LLM Explanation

Dimensionality reduction is a powerful technique for revealing structure and potential clusters in data. However, as the axes are
complex, non-linear combinations of features, they often lack semantic interpretability. Existing visual analytics (VA) methods sup-
port cluster interpretation through feature comparison and interactive exploration, but they require technical expertise and intense
human effort. We present LangLasso, a novel method that complements VA approaches through interactive, natural language descriptions of clusters using large language models (LLMs). It produces human-readable descriptions that make cluster interpretation accessible to non-experts and allow integration of external contextual
knowledge beyond the dataset. We systematically evaluate the reliability of these explanations and demonstrate that LangLasso provides an effective first step for engaging broader audiences in cluster interpretation. The tool is available at langlasso.vercel.app.