From the New World of Word Embeddings: A Comparative Study of Small-World Lexico-Semantic Networks in LLMs

ACL ARR 2025 May Submission3723 Authors

Abstract: Lexico-semantic networks represent words as nodes and their semantic relatedness as edges. While such networks are traditionally constructed using embeddings from encoder-based models or static vectors, embeddings from decoder-only large language models (LLMs) remain underexplored. Unlike encoder models, LLMs are trained with a next-token prediction objective, which does not directly encode the meaning of the current token. In this paper, we construct lexico-semantic networks from the input embeddings of LLMs with varying parameter scales and conduct a comparative analysis of their global and local structures. Our results show that these networks exhibit small-world properties, characterized by high clustering and short path lengths. Moreover, larger LLMs yield more intricate networks with less small-world effects and longer paths, reflecting richer semantic structures and relations. We further validate our approach through analyses of common conceptual pairs, structured lexical relations derived from WordNet, and a cross-lingual semantic network for qualitative words.

Paper Type: Long

Research Area: Semantics: Lexical and Sentence-Level

Research Area Keywords: word embeddings, lexical relationships

Contribution Types: Model analysis & interpretability, Data analysis

Languages Studied: English

Submission Number: 3723