Source note2 min read
Detecting LLM-Generated Tokens in Human--LLM Coauthored Text
Source
arXiv
arxiv.org/abs/2607.21458v1
Source
- Source name: arXiv
- Source kind: paper
- Authors / organization: Yangjun Lu, Hongyi Zhou, Fabian Spill, Kai Ye, Chengchun Shi, Jin Zhu
- Venue: arXiv: cs.AI
- Published: 2026-07-23
- Collected: 2026-07-24
- URL: http://arxiv.org/abs/2607.21458v1
- PDF: https://arxiv.org/pdf/2607.21458v1
- DOI: UNKNOWN
Plain-Language Brief
The paper presents a new method to detect which parts of a text are generated by language models (LLMs) in collaborative human-AI writing, operating at the token level and improving upon existing token-level detection scores. The method uses an adaptive Lepski-type rule to estimate the underlying signal and achieves favorable mean square error performance.
What the Document Says
- The paper discusses a method for detecting parts of a text generated by language models (LLMs) in human-AI collaborative writing.
- The method operates at the token level and uses existing token-level detection scores.
- It smooths adjacent token scores to reduce variability.
- An adaptive Lepski-type rule is used to select the bandwidth according to the local authorship structure.
- The method does not require token-level labeled data for training.
- Theoretically, it characterizes a trade-off and shows favorable mean square error performance.
- Empirically, it demonstrates strong performance against various baselines in both synthetic datasets and realistic ones.
Key Concepts Mentioned
- human-AI collaborative writing
- language models
- token-level detection
- Lepski-type rule
- mean square error
Claims Made by the Document
- The method can accurately detect LLM-generated content in mixed-authorship documents.
- The method achieves favorable mean square error performance.
Evidence Used
- The paper demonstrates strong performance of the method against a wide range of baselines in both synthetic datasets and a realistic dataset.
- Theoretically, it characterizes a trade-off and shows favorable mean square error performance.
Methods / Approach
UNKNOWN
Limitations Stated by the Authors
UNKNOWN
Limitations Noted by the Agent
Agent interpretation — not from the source.
UNKNOWN
Open Questions
UNKNOWN
Notes for Future Q&A
May include interpretation. Labeled where it does.
UNKNOWN
Raw Abstract / Excerpt
The rise of human-AI collaborative writing has created a growing need for fine-grained detection methods that support localizing likely LLM-generated content in mixed-authorship documents. Existing methods for detecting LLM-generated text mainly focus on document-level classification and cannot identify which parts of the text are generated by LLMs. This paper introduces a new method to address this urgent need. Our method operates at the token level, the natural unit of modern language models, and builds on existing token-level detection scores. The key idea is to smooth adjacent token scores to reduce their variability, while using an adaptive Lepski-type rule to select the bandwidth according to the local authorship structure. Our method is simple to implement and does not require token-level labeled data for training. Theoretically, we characterize this trade-off and show that the proposed method achieves favorable mean square error performance in estimating the underlying signal. Empirically, we demonstrate strong performance of our method against a wide range of baselines in both synthetic datasets and a realistic dataset. We deploy a publicly accessible website that implements the methods as well.
