titleTraining Foundation Models with a Single Algorithm
authorsYuda Song, Alvin Zhang, Fahim Tajwar, Daman Arora, Jeff Schneider, Daniel Khashabi, Ruslan Salakhutdinov, J. Andrew Bagnell, Aarti Singh, Andrea Zanette
date2026-10-29
venuearXiv (preprint, not peer reviewed)
idarXiv:2610.40564
affiliationCarnegie Mellon University
upvotes8 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf code
abstractFoundation models are typically trained in stages: pretraining, midtraining, supervised fine-tuning (SFT), and reinforcement learning (RL), with changes in both data and learning algorithms. We show that this algorithmic separation is not fundamental. By deriving suitable RL objectives as maximum-likelihood fitting to model-generated target distributions, we place all of these stages under a single likelihood-based training algorithm, unified training. This perspective turns the foundation-model training lifecycle into a problem of choosing which data to train on, in what proportions, and when, with conventional staged training as a special case. We instantiate this framework in a unified training system that mixes static data and RL generations within a single trainer. Across controlled and real-world experiments, unified training improves the accuracy-compute tradeoff and task coverage while preserving broader capabilities, and provides a stronger starting point for continual learning. This work lays the groundwork for a unified science of foundation-model training, connecting mathematical principles, training infrastructure, and the development of model capabilities.

cite

@misc{song2026training,
  title={Training Foundation Models with a Single Algorithm},
  author={Yuda Song and Alvin Zhang and Fahim Tajwar and Daman Arora and Jeff Schneider and Daniel Khashabi and Ruslan Salakhutdinov and J. Andrew Bagnell and Aarti Singh and Andrea Zanette},
  year={2026},
  eprint={2610.40564},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2610.40564}
}