Timbre used reliability-weighted harmonic consensus to stop multimodal test-time reinforcement learning from reinforcing its own confident mistakes
AspireAI community · arXiv
Label-free test-time reinforcement learning adapts vision-language models using rewards derived from their own predictions, which means a consistent but wrong consensus gets reinforced by majority voting. Timbre builds a 2x2 grid of original and perturbed images crossed with direct-solving and reframing modes, selects pseudo-labels by weighted harmonic aggregation, and shifts modality weights using batch-averaged, temporally smoothed changes in pseudo-label confidence as a reliability signal. Across six benchmarks and three Qwen3-VL model scales it beat TTRV in 16 of 18 benchmark-model settings on adaptation instances and 17 of 18 on held-out instances under matched rollout counts, and the harmonic aggregate is defined as the unique minimizer of a weighted chi-square barycenter problem. The reliability update is a heuristic built from confidence shifts, and the evaluation is confined to Qwen3-VL scales.
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