paper-with-me

Papers

Inconsistent Tokenizations Cause Language Models to be Perplexed by Japanese Grammar

2025-05-26 · Andrew Gambardella, Takeshi Kojima, Yusuke Iwasawa, Yutaka Matsuo

Typical methods for evaluating the performance of language models evaluate their ability to answer questions accurately. These evaluation metrics are acceptable for determining the extent to which language models can understand and reason about text in a general sense, but fail to capture nuanced capabilities, such as the ability of language models to recognize and obey rare grammar points, particularly in languages other than English. We measure the perplexity of language models when confronted with the "first person psych predicate restriction" grammar point in Japanese. Weblab is the only tested open source model in the 7-10B parameter range which consistently assigns higher perplexity to ungrammatical psych predicate sentences than grammatical ones. We give evidence that Weblab's uniformly bad tokenization is a possible root cause for its good performance, and show that Llama 3's perplexity on grammatical psych predicate sentences can be reduced by orders of magnitude (28x difference) by restricting test sentences to those with uniformly well-behaved tokenizations. We show in further experiments on machine translation tasks that language models will use alternative grammar patterns in order to produce grammatical sentences when tokenization issues prevent the most natural sentence from being output.

📄 PDF Abstract BibTeX arXiv:2505.19599

Code (0)

등록된 구현이 없습니다.

Tasks

Machine TranslationSentence

Methods 이 논문이 사용한 방법론

LLaMA LLaMA is a collection of foundation language models ranging from 7B to 65B parameters. It is based on the transformer architecture with various improvements that were…

Similar Papers 제목 키워드 기반

Wine is not v i n. On the Compatibility of Tokenizations across Languages

2021-11-01 · Findings (EMNLP) 2021 11 · Antonis Maronikolakis, Philipp Dufter, Hinrich Schütze

The size of the vocabulary is a central design choice in large pretrained language models, with respect to both performance and memory requirements. Typically, subword tokenization algorithms such as byte pair encoding a…

Wine is Not v i n. -- On the Compatibility of Tokenizations Across Languages

2021-09-13 · Antonis Maronikolakis, Philipp Dufter, Hinrich Schütze

The size of the vocabulary is a central design choice in large pretrained language models, with respect to both performance and memory requirements. Typically, subword tokenization algorithms such as byte pair encoding a…

Improving Self Consistency in LLMs through Probabilistic Tokenization

2024-07-04 · Ashutosh Sathe, Divyanshu Aggarwal, Sunayana Sitaram

Prior research has demonstrated noticeable performance gains through the use of probabilistic tokenizations, an approach that involves employing multiple tokenizations of the same input string during the training phase o…

Language ModelingLanguage Modelling

Language Models are not Equally Robust to Non-Canonical Tokenization across Languages

2026-07-29 · Poulami Ghosh, Preethi Jyothi arxiv

Despite the existence of exponentially many valid tokenizations for a given string, language models operate on a single canonical sequence deterministically produced by the tokenizer, leaving the broader tokenization spa…

Large Language Models are Perplexed by some Political Parties

2026-06-04 · Paul Lerner, François Yvon arxiv

Large Language Models (LLMs) are increasingly used, including in political applications, but their political fairness has been little studied. We assess it using perplexity, posing that a fair model should give equal pro…