activity
20242026
collaborators

7 papers

cs.CR2026

A False Sense of Privacy: Evaluating Textual Data Sanitization Beyond Surface-level Privacy Leakage

Rui Xin, Niloofar Mireshghallah, Shuyue Stella Li +6

Sanitizing sensitive text data typically involves removing personally identifiable information (PII) or generating synthetic data under the assumption that these methods adequately…

cs.CL2026

Are you going to finish that? A Practical Study of the Partial Token Problem

Hao Xu, Alisa Liu, Jonathan Hayase +2

Language models (LMs) are trained over sequences of tokens, whereas users interact with LMs via text. This mismatch gives rise to the partial token problem, which occurs when a use…

cs.CL2026

Broken Tokens? Your Language Model can Secretly Handle Non-Canonical Tokenizations

Brian Siyuan Zheng, Alisa Liu, Orevaoghene Ahia +3

Modern tokenizers employ deterministic algorithms to map text into a single "canonical" token sequence, yet the same string can be encoded as many non-canonical tokenizations using…

cs.CL2026

Infini-gram mini: Exact n-gram Search at the Internet Scale with FM-Index

Hao Xu, Jiacheng Liu, Yejin Choi +2

Language models are trained mainly on massive text data from the Internet, and it becomes increasingly important to understand this data source. Exact-match search engines enable s…

cs.CL2025

SuperBPE: Space Travel for Language Models

Alisa Liu, Jonathan Hayase, Valentin Hofmann +3

The assumption across nearly all language model (LM) tokenization schemes is that tokens should be subwords, i.e., contained within word boundaries. While providing a seemingly rea…

cs.CL2025

OLMoTrace: Tracing Language Model Outputs Back to Trillions of Training Tokens

Jiacheng Liu, Taylor Blanton, Yanai Elazar +28

We present OLMoTrace, the first system that traces the outputs of language models back to their full, multi-trillion-token training data in real time. OLMoTrace finds and shows ver…