titleBuilding Auditable AI Text Detectors with Sparse Autoencoders
authorsLiam Dugan, Callum McDougall, Matthew Denton, Philip Pham, Christine Kaeser-Chen, Chris Callison-Burch
date2026-10-21
venuearXiv (preprint, not peer reviewed)
idarXiv:2610.30006
affiliationGoogleDeepMind
upvotes14 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf code
abstractAI-generated text detectors are increasingly deployed in consequential settings---peer review, education, admissions, journalism, and content moderation---where their outputs directly affect individuals. Yet the strongest detectors are fine-tuned neural classifiers whose decisions are opaque, while transparent alternatives (stylometric and linguistic-feature classifiers) underperform them by wide margins. We present a pipeline that converts a fine-tuned neural detector into a classifier that operates on human-readable concepts. We accomplish this by training sparse autoencoders (SAEs) directly on a detector's residual stream, assigning auto-interpretation labels to each SAE feature, and retaining only features whose generated descriptions pass a global fidelity threshold. We then train a lightweight classifier on just the interpretable features. We find that our SAEs recover latent concepts that correspond to highly specific and predictive linguistic "tells" of AI-generated text. Classifiers built on these extracted features are not only highly interpretable but exhibit stronger performance on out-of-distribution texts than either neural or stylometric alternatives.

cite

@misc{dugan2026building,
  title={Building Auditable AI Text Detectors with Sparse Autoencoders},
  author={Liam Dugan and Callum McDougall and Matthew Denton and Philip Pham and Christine Kaeser-Chen and Chris Callison-Burch},
  year={2026},
  eprint={2610.30006},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2610.30006}
}