Provably Learning from Modern Language Models via Low Logit Rank

Fuente: arXiv
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Autores principales: Golowich, Noah, Liu, Allen, Shetty, Abhishek
Formato: Preprint
Publicado: 2025
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author Golowich, Noah
Liu, Allen
Shetty, Abhishek
author_facet Golowich, Noah
Liu, Allen
Shetty, Abhishek
contents While modern language models and their inner workings are incredibly complex, recent work (Golowich, Liu & Shetty; 2025) has proposed a simple and potentially tractable abstraction for them through the observation that empirically, these language models all seem to have approximately low logit rank. Roughly, this means that a matrix formed by the model's log probabilities of various tokens conditioned on certain sequences of tokens is well approximated by a low rank matrix. In this paper, our focus is on understanding how this structure can be exploited algorithmically for obtaining provable learning guarantees. Since low logit rank models can encode hard-to-learn distributions such as noisy parities, we study a query learning model with logit queries that reflects the access model for common APIs. Our main result is an efficient algorithm for learning any approximately low logit rank model from queries. We emphasize that our structural assumption closely reflects the behavior that is empirically observed in modern language models. Thus, our result gives what we believe is the first end-to-end learning guarantee for a generative model that plausibly captures modern language models.
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id arxiv_https___arxiv_org_abs_2512_09892
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Provably Learning from Modern Language Models via Low Logit Rank
Golowich, Noah
Liu, Allen
Shetty, Abhishek
Machine Learning
Artificial Intelligence
Data Structures and Algorithms
While modern language models and their inner workings are incredibly complex, recent work (Golowich, Liu & Shetty; 2025) has proposed a simple and potentially tractable abstraction for them through the observation that empirically, these language models all seem to have approximately low logit rank. Roughly, this means that a matrix formed by the model's log probabilities of various tokens conditioned on certain sequences of tokens is well approximated by a low rank matrix. In this paper, our focus is on understanding how this structure can be exploited algorithmically for obtaining provable learning guarantees. Since low logit rank models can encode hard-to-learn distributions such as noisy parities, we study a query learning model with logit queries that reflects the access model for common APIs. Our main result is an efficient algorithm for learning any approximately low logit rank model from queries. We emphasize that our structural assumption closely reflects the behavior that is empirically observed in modern language models. Thus, our result gives what we believe is the first end-to-end learning guarantee for a generative model that plausibly captures modern language models.
title Provably Learning from Modern Language Models via Low Logit Rank
topic Machine Learning
Artificial Intelligence
Data Structures and Algorithms
url https://arxiv.org/abs/2512.09892