Ruozhen He

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.
We introduce HypoExplore, an agentic framework that formulates model discovery as a hypothesis-driven scientific inquiry. Given a human-specified high-level research direction, HypoExplore ideates, implements, evaluates, and improves neural architectures through evolutionary branching. Hypotheses are generated using a large language model by selecting a parent hypothesis to build upon, guided by a dual strategy that balances exploiting validated principles with resolving uncertain ones. Our proposed framework maintains a Trajectory Tree that records the lineage of all proposed architectures, and a Hypothesis Memory Bank that actively tracks associated confidence scores acquired through experimental evidence. After each experiment, multiple feedback agents analyze the results from different perspectives and consolidate their findings into hypothesis confidence updates. Under minimal research directions, HypoExplore discovers a model that achieves top results on two medical imaging tasks on MedMNIST, an improved encoder for named entity recognition on FiNER-ORD, and a lightweight 0.7M parameter model on CIFAR-10 that reaches 94.1% accuracy and transfers well to other benchmarks. Our analysis of hypothesis confidence scores across evolutionary lineages suggest that HypoExplore not only discovers stronger architectures, but can help build a genuine understanding of the design space.
Advanced chart question answering requires both precise perception of small visual elements and multi-step reasoning across several subplots. While existing MLLMs are strong at understanding single plots, they often struggle with multi-step reasoning across multiple subplots. We propose HierVA, a hierarchical visual agent framework for chart reasoning that iteratively constructs and updates a working context in a joint image–text space. A high-level manager generates plans and maintains a compact context containing only key information, while specialized sub-agents perform reasoning, gather evidence, and return results. In particular, the agent maintains separate visual and textual contexts, using a zoom-in tool to restrict the visual context. Experiments on the chart reasoning benchmarks demonstrate consistent improvements over strong multimodal baselines, and ablation studies verify that hierarchical architecture, limited visual context, and distilled context contribute complementary gains.
Existing visual grounding benchmarks primarily evaluate alignment between image regions and literal referring expressions, where models can often succeed by matching a prominent named category. This leaves a complementary but under-examined setting: scenario-based visual grounding, where the target must be inferred from roles, intentions, and relational context rather than explicit object naming alone. We introduce Referring Scenario Comprehension (RSC), a benchmark designed to study this setting. RSC queries describe roles, goals, and contextual cues, and deliberately reference distractor objects to reduce lexical shortcutting. Each instance is annotated with interpretable difficulty tags for uniqueness, clutter, size, overlap, and position, which expose distinct failure modes and support fine-grained analysis. RSC contains approximately 31k training examples, 4k in-domain test examples, and a 3k out-of-distribution split with unseen object categories to test generalization beyond category co-occurrence. We further propose ScenGround, a curriculum reasoning method serving as a reference point for this setting, combining supervised warm-starting with difficulty-aware reinforcement learning. Experiments show that scenario-based queries expose systematic shortcut failures in current models that standard benchmarks do not reveal, and that curriculum training improves performance on challenging slices and transfers robust improvement to standard benchmarks.