arXiv AI

Benefit and Cost of Random-Token Replacement under Repeated Data: A Known-Entropy Decomposition and Evidence from Ten Real Corpora

arXiv Machine Learning
Jun 25

Internal Data Repetition Destroys Language Models

arXiv:2606. 24998v1 Announce Type: new Abstract: Language models are running out of high-quality training data, and even aggressively deduplicated corpora retain some amount of repetition.

By Jessica Chudnovsky, Joshua Kazdan, Noam Levi, Rylan Schaeffer, Yegor Denisov-Blanch, Bo He, Mehmet Donmez, Sanmi Koyejo, David Donoho
arXiv Machine Learning
Jul 15

Extractable Memorization From First Principles

arXiv:2607. 12649v1 Announce Type: new Abstract: Recent work on extractable memorization in LLMs suffers from two contrasting validity problems.

By A. Feder Cooper, Marika Swanberg, Jamie Hayes, Lea Duesterwald, Christopher De Sa, Daniel E. Ho, Mark A. Lemley, Percy Liang
arXiv Machine Learning
Oct 12

Forecasting Corpus-Sampling Disagreement in Masked Text Reconstruction

The paper investigates how much a masked‑text reconstruction predictor’s outputs would differ if a second corpus were collected from the same population. Using a smoothed predictor based on token‑pair counts, the authors derive a first‑order formula for expected disagreement between predictors trained on two independent corpora, accounting for document length, random context counts, and token‑offset correlations. Experiments on TinyStories, WikiText‑103, and CNN/DailyMail show that increasing corpus size from 512 to 2,048 chunks of 64 tokens reduces disagreement only modestly (5–40 %), and that forecast accuracy improves with larger reference corpora and a source‑split jackknife correction. whyItMatters:"The study provides a practical method to estimate how much predictor outputs would change with additional data, informing decisions about data collection and model robustness in masked‑text reconstruction tasks."

By Hare Krishna
arXiv Machine Learning
4d ago

Less Loss, Fixed Weights: Logit Corrections for Forgetting

The paper investigates whether a language model’s forgetting—worsening performance on standard web text after fine‑tuning or further pretraining—can be mitigated by simple, fixed adjustments to its final token predictions. By fitting a vocabulary‑wide bias (a token‑specific bonus or penalty) and optionally a temperature scaling, the authors evaluate recovery across 14 base‑to‑derived model pairs ranging from 1B to 7B parameters. Results show modest gains: up to 10% recovery with bias alone and up to 36% when combined with temperature, though models further pretrained on math lose the most and recover little; even in a controlled simulation with random damage, the bias‑plus‑temperature fix recovers 29%.

By Hanyu Yang
arXiv AI
Oct 1

Mitigating Memorization In Language Models

The paper explores ways to reduce the memorization of training data in language models, testing three regularizer-based, three finetuning-based, and eleven machine unlearning methods—five of which are newly introduced. It introduces TinyMem, a lightweight suite of small models for rapid testing of these mitigation techniques, and shows that unlearning methods, particularly BalancedSubnet, outperform others in removing memorized content while maintaining task performance. The study also finds that regularizer-based approaches are slow and ineffective, while finetuning methods are costly, especially when high accuracy is required.

By Mansi Sakarvadia, Aswathy Ajith, Arham Khan, Nathaniel Hudson, Caleb Geniesse, Kyle Chard, Yaoqing Yang, Ian Foster, Michael W. Mahoney