ResearchResearch paperInterpretability1 source · Oct 21, 2026

Building Auditable AI Text Detectors with Sparse Autoencoders

We present a pipeline that converts a fine-tuned neural detector into a classifier that operates on human-readable concepts.

Key points

  • AI-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 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 find that our SAEs recover latent concepts that correspond to highly specific and predictive linguistic "tells" of AI-generated text.

Sources (1)

  • [1]Building Auditable AI Text Detectors with Sparse Autoencoders
    arXiv (AI, ML, NLP, CV, robotics, multi-agent) · Oct 21, 04:41 PM
    We present a pipeline that converts a fine-tuned neural detector into a classifier that operates on human-readable concepts.
    AI-generated text detectors are increasingly deployed in consequential settings---peer review, education, admissions, journalism, and content moderation---where their outputs directly affect individuals.

Extractive summary: sentences quoted from the sources.

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