🤖 AI Summary
To address the lack of fine-grained reward signals and high annotation cost for trajectory labeling in training LLM-based GUI agents, this paper proposes the Progress Reward Model (ProgRM). Methodologically, ProgRM introduces: (1) a dense progress feedback mechanism grounded in task completion degree, overcoming the binary outcome-only limitation of conventional Outcome Reward Models (ORMs); and (2) an LCS-based self-labeling algorithm that automatically identifies critical steps and generates progress labels via longest common subsequence alignment—eliminating manual annotation. The framework integrates online reinforcement learning, progress prediction modeling, and self-supervised reward annotation. Evaluated across diverse GUI benchmarks, ProgRM significantly improves task success rates, outperforming leading closed-source LLMs and ORM baselines, and achieves state-of-the-art performance.
📝 Abstract
LLM-based (Large Language Model) GUI (Graphical User Interface) agents can potentially reshape our daily lives significantly. However, current LLM-based GUI agents suffer from the scarcity of high-quality training data owing to the difficulties of trajectory collection and reward annotation. Existing works have been exploring LLMs to collect trajectories for imitation learning or to offer reward signals for online RL training. However, the Outcome Reward Model (ORM) used in existing works cannot provide finegrained feedback and can over-penalize the valuable steps in finally failed trajectories. To this end, we propose Progress Reward Model (ProgRM) to provide dense informative intermediate rewards by predicting a task completion progress for each step in online training. To handle the challenge of progress reward label annotation, we further design an efficient LCS-based (Longest Common Subsequence) self-annotation algorithm to discover the key steps in trajectories and assign progress labels accordingly. ProgRM is evaluated with extensive experiments and analyses. Actors trained with ProgRM outperform leading proprietary LLMs and ORM-trained actors, illustrating the effectiveness of ProgRM. The codes for experiments will be made publicly available upon acceptance.