@inproceedings{cognetta-etal-2024-two,
title = "Two Counterexamples to Tokenization and the Noiseless Channel",
author = "Cognetta, Marco and
Zouhar, Vil{\'e}m and
Moon, Sangwhan and
Okazaki, Naoaki",
editor = "Calzolari, Nicoletta and
Kan, Min-Yen and
Hoste, Veronique and
Lenci, Alessandro and
Sakti, Sakriani and
Xue, Nianwen",
booktitle = "Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)",
month = may,
year = "2024",
address = "Torino, Italia",
publisher = "ELRA and ICCL",
url = "https://aclanthology.org/2024.lrec-main.1469/",
pages = "16897--16906",
abstract = "In Tokenization and the Noiseless Channel (Zouhar et al., 2023), R{\'e}nyi efficiency is suggested as an intrinsic mechanism for evaluating a tokenizer: for NLP tasks, the tokenizer which leads to the highest R{\'e}nyi efficiency of the unigram distribution should be chosen. The R{\'e}nyi efficiency is thus treated as a predictor of downstream performance (e.g., predicting BLEU for a machine translation task), without the expensive step of training multiple models with different tokenizers. Although useful, the predictive power of this metric is not perfect, and the authors note there are additional qualities of a good tokenization scheme that R{\'e}nyi efficiency alone cannot capture. We describe two variants of BPE tokenization which can arbitrarily increase R{\'e}nyi efficiency while decreasing the downstream model performance. These counterexamples expose cases where R{\'e}nyi efficiency fails as an intrinsic tokenization metric and thus give insight for building more accurate predictors."
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<abstract>In Tokenization and the Noiseless Channel (Zouhar et al., 2023), Rényi efficiency is suggested as an intrinsic mechanism for evaluating a tokenizer: for NLP tasks, the tokenizer which leads to the highest Rényi efficiency of the unigram distribution should be chosen. The Rényi efficiency is thus treated as a predictor of downstream performance (e.g., predicting BLEU for a machine translation task), without the expensive step of training multiple models with different tokenizers. Although useful, the predictive power of this metric is not perfect, and the authors note there are additional qualities of a good tokenization scheme that Rényi efficiency alone cannot capture. We describe two variants of BPE tokenization which can arbitrarily increase Rényi efficiency while decreasing the downstream model performance. These counterexamples expose cases where Rényi efficiency fails as an intrinsic tokenization metric and thus give insight for building more accurate predictors.</abstract>
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%0 Conference Proceedings
%T Two Counterexamples to Tokenization and the Noiseless Channel
%A Cognetta, Marco
%A Zouhar, Vilém
%A Moon, Sangwhan
%A Okazaki, Naoaki
%Y Calzolari, Nicoletta
%Y Kan, Min-Yen
%Y Hoste, Veronique
%Y Lenci, Alessandro
%Y Sakti, Sakriani
%Y Xue, Nianwen
%S Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
%D 2024
%8 May
%I ELRA and ICCL
%C Torino, Italia
%F cognetta-etal-2024-two
%X In Tokenization and the Noiseless Channel (Zouhar et al., 2023), Rényi efficiency is suggested as an intrinsic mechanism for evaluating a tokenizer: for NLP tasks, the tokenizer which leads to the highest Rényi efficiency of the unigram distribution should be chosen. The Rényi efficiency is thus treated as a predictor of downstream performance (e.g., predicting BLEU for a machine translation task), without the expensive step of training multiple models with different tokenizers. Although useful, the predictive power of this metric is not perfect, and the authors note there are additional qualities of a good tokenization scheme that Rényi efficiency alone cannot capture. We describe two variants of BPE tokenization which can arbitrarily increase Rényi efficiency while decreasing the downstream model performance. These counterexamples expose cases where Rényi efficiency fails as an intrinsic tokenization metric and thus give insight for building more accurate predictors.
%U https://aclanthology.org/2024.lrec-main.1469/
%P 16897-16906
Markdown (Informal)
[Two Counterexamples to Tokenization and the Noiseless Channel](https://aclanthology.org/2024.lrec-main.1469/) (Cognetta et al., LREC-COLING 2024)
ACL
- Marco Cognetta, Vilém Zouhar, Sangwhan Moon, and Naoaki Okazaki. 2024. Two Counterexamples to Tokenization and the Noiseless Channel. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), pages 16897–16906, Torino, Italia. ELRA and ICCL.