LEAF: Growing Trees Without Branching for Speech-Aware Large Language Model Post-Training

Excerpt

arXiv:2606.07610v2 Announce Type: replace-cross Abstract: State-of-the-art GRPO-style methods for speech-aware large language model post-training suffer from coarse credit assignment, broadcasting the same terminal-reward advantage to every token in a response. This ignores useful structure within rollout batches, where speech-conditioned completions often share prefixes before diverging at important decisions. We propose Low-rank Exploration with Adaptive Forking (LEAF), a retrospective tree-ba