👋 Hi everyone! I’m a first-year Computer Science Ph.D. student at the University of Pennsylvania, advised by Eric Wong. I’m fortunate to receive the NSF Graduate Research Fellowship (GRFP) in 2025. Before that, I graduated with a B.S. in Statistics and Machine Learning from Carnegie Mellon University (CMU), where I was advised by Prof. Graham Neubig and Prof. Pengfei Liu.

🧠 My current research interests include:

• Multimodal Foundation Models: Building and understanding AI models that can perceive, reason, and interact with the world effectively.
• Trustworthy and Robust AI: Ensuring AI systems are reliable, honest, and safe by developing tools to detect factual inaccuracies, prevent hallucinations, adapt AI behavior to dynamic human norms, and strengthen robustness against adversarial attacks.

⛳ I was also a student-athlete, playing NCAA Women’s Golf at CMU.

📩 Feel free to contact me about any research/job opportunities or questions you have!

Academic Service

🔎 Reviewer: NeurIPS (2024, 2025), ICLR (2025, 2026), AISTATS (2025), COLM (2025)

Selected Publications

⬇️ Below are some of my recent publications (full publication see here):

Thinking with Generated Images
Ethan Chern⁺, Zhulin Hu⁺, Steffi Chern⁺, Siqi Kou, Jiadi Su, Yan Ma, Zhijie Deng, Pengfei Liu
Preprint. [paper] [github]

Can Large Language Models be Trusted for Evaluation? Scalable Meta-Evaluation of LLMs as Evaluators via Agent Debate
Steffi Chern, Ethan Chern, Graham Neubig, Pengfei Liu
Accepted to the AAAI 2025 AI4Research (Oral) [paper] [github]

BeHonest: Benchmarking Honesty in Large Language Models
Steffi Chern⁺, Zhulin Hu⁺, Yuqing Yang⁺, Ethan Chern, Yuan Guo, Jiahe Jin, Binjie Wang, Pengfei Liu
Preprint. [paper] [github] [website]

FacTool: Factuality Detection in Generative AI - A Tool Augmented Framework for Multi-Task and Multi-Domain Scenarios
I-Chun Chern, Steffi Chern, Shiqi Chen, Weizhe Yuan, Kehua Feng, Chunting Zhou, Junxian He, Graham Neubig, Pengfei Liu
Accepted to COLM 2025. [paper] [github] [website]