Glitch Tokens in Large Language Models: Categorization Taxonomy and Effective Detection
<|reference_start|>Glitch Tokens in Large Language Models: Categorization Taxonomy and Effective Detection: With the expanding application of Large Language Models (LLMs) in various domains, it becomes imperative to comprehensively investigate their unforeseen behaviors and consequent outcomes. In this study, we introduce and systematically explore the phenomenon of "glitch tokens", which are anomalous tokens produced by established tokenizers and could potentially compromise the models' quality of response. Specifically, we experiment on seven top popular LLMs utilizing three distinct tokenizers and involving a totally of 182,517 tokens. We present categorizations of the identified glitch tokens and symptoms exhibited by LLMs when interacting with glitch tokens. Based on our observation that glitch tokens tend to cluster in the embedding space, we propose GlitchHunter, a novel iterative clustering-based technique, for efficient glitch token detection. The evaluation shows that our approach notably outperforms three baseline methods on eight open-source LLMs. To the best of our knowledge, we present the first comprehensive study on glitch tokens. Our new detection further provides valuable insights into mitigating tokenization-related errors in LLMs.<|reference_end|>
@article{li2024glitch,
    title={Glitch Tokens in Large Language Models: Categorization Taxonomy and
  Effective Detection},
    author={Yuxi Li, Yi Liu, Gelei Deng, Ying Zhang, Wenjia Song, Ling Shi,
  Kailong Wang, Yuekang Li, Yang Liu and Haoyu Wang},
    journal={arXiv preprint arXiv:2404.09894},
    year={2024},
    archivePrefix={arXiv},
    eprint={2404.09894},
    primaryClass={cs.CL cs.SE}
}