Portrait de Fengyuan Liu

Fengyuan Liu

Maîtrise recherche - McGill
Superviseur⋅e principal⋅e
Co-supervisor
Sujets de recherche
Agent basé sur un LLM
Alignement de l'IA
Apprentissage continu
Apprentissage décentralisé
Apprentissage fédéré
Apprentissage multimodal
Apprentissage par transfert
Apprentissage profond
Apprentissage sur variétés
Compression de modèles
Grands modèles de langage (LLM)
IAG (Intelligence Artificielle Générale)
Optimisation
Optimisation décentralisée
Traitement du langage naturel
XAI (IA explicable)

Publications

WebArena-Pro: A Heterogeneous, Multimodal, Reproducible Benchmark for Web Agents
Fatemeh Pesaran zadeh
Weijian Qi
Alexander Miller
Junyi Song
Yunjia Tian
Dongjin Kang
Seyeon Choi
Ewen Gueguen
Zeyi Liao
Mengqi Yuan
Alexandre Lacoste
Huan Sun … (voir 2 de plus)
Gunhee Kim
Web agents powered by large language and vision-language models are increasingly applied to realistic browser work that spans heterogeneous … (voir plus)applications, multimodal content, and stateful workflows. However, existing reproducible web-agent benchmarks cover only a small number of web applications drawn from a few software categories, and restrict modality to text and vision. Live benchmarks broaden site coverage but sacrifice reproducibility, since pages and data drift between runs. Moreover, existing benchmarks do not meaningfully evaluate whether agents can understand and use audio and video content embedded within web tasks. To address these gaps, we introduce WebArena-Pro, a benchmark comprising 300 tasks across 20 self-hosted web applications in six domain categories, spanning distinct interface conventions, workflows, and data models. Across the evaluated agents, the best performance is achieved by Gemini 3.1 Pro, which attains 37.0 % success under a 50-step budget, while open-source models' performance does not exceed 27.7% success. Among reproducible, human-curated web agent benchmarks, WebArena-Pro provides the broadest application coverage and the most comprehensive multimodal support to date. The benchmark treats audio and video as core observations alongside text and vision, with dedicated actions for extracting information from each. WebArena-Pro runs each task in isolation and supports reproducible, parallel evaluation. Tasks are authored through a dedicated annotator interface, filtered by LLM-assisted triage, and finally validated by humans before release.
BRIDGE: Predicting Human Task Completion Time From Model Performance
Evaluating the real-world capabilities of AI systems requires grounding benchmark performance in human-interpretable measures of task diffic… (voir plus)ulty. Existing approaches that rely on direct human task completion time annotations are costly, noisy, and difficult to scale across benchmarks. In this work, we propose BRIDGE, a unified psychometric framework that learns the latent difficulty scale from model responses and anchors it to human task completion time. Using a two-parameter logistic Item Response Theory model, we jointly estimate latent task difficulty and model capability from model performance data across multiple benchmarks. We demonstrate that latent task difficulty varies linearly with the logarithm of human completion time, allowing human task completion time to be inferred for new benchmarks from model performance alone. Leveraging this alignment, we forecast frontier model capabilities in terms of human task length and independently reproduce METR's exponential scaling results, with the 50% solvable task horizon doubling approximately every 6 months.