arXiv Computation and Language
Sep 2

Toppling the Hierarchy in Byte-level Language Modeling

The paper investigates why current byte‑level language models, which use a hierarchical structure that down‑samples to words and then upsamples back to bytes, struggle with precise character manipulation. Experiments show that pure byte‑level models outperform hierarchical variants on character‑level tasks, and that byte‑level attention is the key component driving this advantage. The study explains the trade‑off between computational efficiency and fine‑grained character understanding in hierarchical byte models.

By Lukas Edman, Alexander Fraser
arXiv Computation and Language
Sep 15

To Each Language Its Tokenizer: Modular Tokenizers for Efficient Multilingual LLMs

The paper proposes a modular tokenizer framework for multilingual large language models, allowing the creation of language‑specific subtokenizers that match monolingual compression quality. It introduces a pretraining strategy that samples these subtokenizers to limit predictions to relevant vocabularies, enabling efficient training and inference. This approach reduces memory usage and speeds up inference without compromising performance.

By Franck Signe, Hippolyte Pilchen, Fran\c{c}ois Yvon, \'Edouard Grave
arXiv Computation and Language
Sep 14

Doc2FRC: Length-Consistent Document-Level Machine Translation via Fixed-Range Chunking

Doc2FRC introduces Fixed-Range Chunking (FRC), a dynamic programming method that partitions documents into chunks of a predefined length interval, ensuring consistent length distributions during training and inference. This approach reduces train-test length mismatch, mitigates n-gram repetition, and improves translation quality for 7B LLMs compared to direct Doc2Doc fine-tuning. Experiments on IWSLT2017 and a new 10-language test set, GlobVDoc, demonstrate that FRC outperforms existing document-level machine translation methods and enhances out-of-distribution translation performance.

By Xiaotian Wang, Youyuan Lin, Zhan Shen, Hitomi Yanaka