do-you-really-need-to-pretrain-q-functions-for-online-rl-fine-tuning--930f70c9·1 events·first seen Aliases: Do You Really Need to Pretrain Q-Functions for Online RL Fine-Tuning?
A new arXiv paper systematically examines whether pretraining Q-functions on offline data actually helps when fine-tuning a pretrained policy via online RL, finding that naive Q-function pretraining often provides little benefit over random initialization. The authors attribute this to a fundamental mismatch between the pretrained Q-function's target policy and the policy that online fine-tuning converges to. They propose Initialization via Policy Ensemble (IPE), which trains multiple diverse policies and pools their rollouts to bootstrap Q-function learning, achieving an average 1.26x improvement over naive Q-function pretraining on continuous control benchmarks.