When New Generators Arrive: Lifelong Machine-Generated Text Attribution via Ridge Feature Transfer
Summary
RidgeFT is a lightweight analytic update framework designed for lifelong Machine-Generated Text (MGT) attribution, addressing the challenge of continuously incorporating new text generators while preserving recognition of previously seen ones. This framework trains a task-aware encoder on an initial generator set, then freezes it, storing only compact class-wise sufficient statistics. It employs covariance calibration to suppress generator-irrelevant variations, uses fixed random features to enhance representation capacity, and updates new classes via closed-form ridge regression without requiring exemplar replay. Across multi-topic evaluations using P3, P4, and P5 protocols on MGT-Academic and AIGTBench datasets, RidgeFT consistently outperforms baselines. It achieves a 0.886 full-F1, 0.902 old-class F1, and 0.804 new-class F1 under the P5 protocol, improving full-F1 by 0.037 and new-class F1 by 0.107 over the strongest baselines, demonstrating superior data efficiency.
Key takeaway
For AI Scientists or Machine Learning Engineers developing machine-generated text attribution systems, RidgeFT offers a robust and efficient solution for adapting to continuously emerging large language models. You should consider integrating its replay-free analytic update framework to maintain high accuracy on both old and new generators, especially under low-resource conditions. This approach avoids catastrophic forgetting and costly full model retraining, allowing your systems to evolve scalably. Be mindful of its statistical storage requirements, though low-precision and merged statistics can significantly reduce this footprint.
Key insights
Lifelong MGT attribution benefits from frozen encoders and analytic updates, balancing new-class adaptation with old-class retention without replay.
Principles
- Decouple new generator learning from deep representation updates.
- Stable representations enable efficient incremental knowledge absorption.
- Analytic updates via sufficient statistics avoid catastrophic forgetting.
Method
RidgeFT trains an encoder, freezes it, then uses covariance calibration, isotropic random feature lifting, and class-balanced ridge regression with sufficient statistics for replay-free, closed-form incremental updates.
In practice
- Employ bf16 precision for class statistics to reduce storage.
- Use merged bf16 statistics for new-class-only incremental updates.
- Consider per-class bf16 for updates adding samples to old classes.
Topics
- Machine-Generated Text Attribution
- Lifelong Learning
- Continual Learning
- Ridge Regression
- Random Features
- Large Language Models
Best for: Research Scientist, AI Scientist, Machine Learning Engineer, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.AI updates on arXiv.org.