arXiv Computation and Language

Representation of syntax in LLMs through the lens of linear distance and similarity-aware entropy

arXiv Computation and Language
Aug 31

Tracing the complexity profiles of different linguistic phenomena through the intrinsic dimension of LLM representations

The paper investigates the intrinsic dimension (ID) of large language model (LLM) representations as an indicator of linguistic complexity. By comparing ID across model layers for coordination vs. subordination, right‑branching vs. center‑embedding, and unambiguous vs. ambiguous attachment, the authors find consistent ID differences that align with established complexity contrasts. Experiments across six LLMs, including representational similarity and layer pruning analyses, confirm that more complex phenomena produce higher ID profiles, with peaks occurring at different layers for each contrast.

By Marco Baroni, Emily Cheng, Iria de-Dios-Flores, Francesca Franzon
arXiv Computation and Language
5d ago

How Much Does Corpus Choice Change Dependency-Distance Estimates?

The study examined how the choice of corpus affects estimates of dependency distance in language. By comparing 38 pairs of treebanks from the same language, the authors found that cross-treebank agreement was only moderate, with nearly 40% of language orderings reversed when switching treebanks. Treebank selection explained about 29% of the variance, a discrepancy that far exceeds within-treebank sampling error and persists across multiple preprocessing settings, yet all treebanks still supported the principle of dependency-length minimization.

By Sirui Chen
arXiv Computation and Language
Aug 27

The Changing Geometry of Grammar: Dimensionality and Neighborhood Reorganization across Transformer Layers

The paper studies how transformer representations evolve across layers by examining the intrinsic dimensionality (ID) of token embeddings and their neighborhood structures. It finds that closed‑class tokens expand and collapse earlier than open‑class tokens, and that these changes are linked to shifts in local geometry. The authors compare encoder and decoder models, showing distinct layer‑wise behaviors, and demonstrate that geometric features alone can predict a token’s part‑of‑speech and reveal how semantic content changes across layers.

By Samuele Vallisa, Federico Ravenda, Claudio Palominos, Rui He, Andrea Raballo, Antonietta Mira, Philipp Homan, Wolfram Hinzen