GUI agent training wasted most of its rollouts on steps it had already mastered, and checkpointing past them cut environment interaction by 56-61%
AspireAI community · arXiv (cs.AI)
Trajectory-level GRPO repeatedly replays full trajectories from the task root, so already-mastered prefixes are re-executed before the agent ever reaches the hard states that need learning. This framework builds reusable intermediate checkpoints from successful expert trajectories, picks pivots by action disagreement to find genuinely uncertain decisions, and then expands policy responsibility progressively from local steps to suffixes to the root. Across MobileGym and CUA-Gym-Hub it reduced environment interaction by 56-61% relative to vanilla GRPO while improving task performance. The limitation: the gains are measured on two GUI RL environments, and the method needs successful expert trajectories to build its checkpoints from.
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Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.