Haofu Liao

Author directory

2026

We present Trace2Ground, a large-scale web GUI grounding dataset and benchmark built by parsing HTML/DOM to obtain candidate interface elements and using large language models to simulate interaction traces and natural-language instructions. Existing datasets primarily target instructions solvable by matching the target element’s visible text, while real-world GUI tasks may require grounding under user scenarios, duplicate candidates, and relational descriptions. Trace2Ground targets these under-explored stress regimes through three curated splits: PragmaMind, where instructions describe user scenarios without naming UI elements; ContextTwin, where multiple elements share identical visible text and the correct target must be selected using interaction context; and RelateLoc, where the target is specified via spatial or structural relations to nearby anchors. We construct the dataset via an automated pipeline that extracts candidates from HTML/DOM structure, synthesizes traces and instructions with LLMs, and applies multi-view visual checks. Strong specialist GUI grounders underperform on these regimes despite reaching around 90% on ScreenSpot, exposing a gap not addressed by existing GUI training data. Standard supervised fine-tuning on Trace2Ground improves the base model’s performance on our curated regimes by 42.3% on average and yields zero-shot transfer to standard GUI benchmarks, including a 9.8% average improvement on the non-web ScreenSpot-Pro benchmark across six desktop domains.

2025

Language models have led to leap forward in web automation. The current web automation approaches take the current web state, history actions, and language instruction as inputs to predict the next action, overlooking the importance of history states. However, the highly verbose nature of web page states can result in long input sequence and sparse information, hampering the effective utilization of history states. In this paper, we propose a novel web history compressor approach to turbocharge web automation using history states. Our approach employs a history compressor module that distills the most task-relevant information from each history state into a fixed-length short representation, mitigating the challenges posed by the highly verbose history states. Experiments are conducted on the Mind2Web and WebLINX datasets to evaluate the effectiveness of our approach. Results show that our approach obtains 1.2-5.4% absolute accuracy improvements compared to the baseline approach without history inputs.

2024

Visual document understanding (VDU) is a challenging task that involves understanding documents across various modalities (text and image) and layouts (forms, tables, etc.). This study aims to enhance generalizability of small VDU models by distilling knowledge from LLMs. We identify that directly prompting LLMs often fails to generate informative and useful data. In response, we present a new framework (called DocKD) that enriches the data generation process by integrating external document knowledge. Specifically, we provide an LLM with various document elements like key-value pairs, layouts, and descriptions, to elicit open-ended answers. Our experiments show that DocKD produces high-quality document annotations and surpasses the direct knowledge distillation approach that does not leverage external document knowledge. Moreover, student VDU models trained with solely DocKD-generated data is not only comparable to those trained with human-annotated data on in-domain tasks but also significantly excel them on out-of-domain tasks.