Hi, I'm Ziwei.

I am a fifth-year Ph.D. student in Computer Science at Harvard University, advised by Prof. Elena Glassman. Currently, my research has two threads:

  • AI-resilient interfaces. As LLMs flood people with more information than they can read, I seek to empower people to process information at scale, while ensuring that potential misalignments between human and AI can be easily noticed, judged, and recovered from, a concept I formalize as AI-resiliency.
  • LLM evaluation. I design benchmarks and multi-turn evaluations that test how LLMs handle realistic user requests, such as underspecified or mixed-language queries.

During my Ph.D., I interned at Adobe Research and Autodesk Research and co-led LLM evaluation projects at Scale AI.

Before coming to Harvard, I graduated with a bachelors in Computer Science and Mathematics from Cornell University (May 2021).

I'm on the job market for industry research scientist and engineering roles — feel free to reach out!

Publications
Sampling Reveals Style: Unsupervised, Training-Free Discovery of Prompt-Conditional Stylistic Axes in LLM Activations
Ajit Mallavarapu, Ziwei Gu
EMNLP 2026 BlackboxNLP Workshop
paper

We propose a method to extract the style dimensions people actually care about just by sampling the same prompt many times and running PCA on the model's activations, with no training needed.

AbstractExplorer: Leveraging Structure-Mapping Theory to Enhance Comparative Close Reading at Scale
Ziwei Gu, Joyce Zhou, Ning-Er (Nina) Lei, Jonathan K. Kummerfeld, Mahmood Jasim, Narges Mahyar, Elena L. Glassman
UIST 2025
paper / video

Large document collections can be overwhelming. We investigate ways to enable comparative close reading at scale by ordering, aligning, and highlighting analogous sentence segments.

Why Do Skimmers Perform Better with Grammar-Preserving Text Saliency Modulation (GP-TSM)? Evidence from an Eye Tracking Study
Ziwei Gu, Owen Raymond, Naser Al Madi, Elena L. Glassman
CHI 2024 Late Breaking Work
paper / video

Through an eye-tracking study, we uncover unique gaze patterns when people read with GP-TSM, an LLM-powered reading support tool, and explain how it shapes the reading experience.

An AI-Resilient Text Rendering Technique for Reading and Skimming Documents
Ziwei Gu, Ian Arawjo, Kenneth Li, Jonathan K. Kummerfeld, Elena L. Glassman
CHI 2024
paper / video

AI summaries can be helpful but also unreliable. We design an LLM-powered technique that enhances reading efficiency while making readers resilient to errors in summaries.

Supporting Sensemaking of Large Language Model Outputs at Scale
Katy Ilonka Gero, Chelse Swoopes, Ziwei Gu, Jonathan K. Kummerfeld, Elena L. Glassman
CHI 2024
Honorable Mention Award
paper

LLMs can quickly generate many responses to a single prompt. Each might be better in some way. We explore how to present many LLM responses at once to support sensemaking at scale.

Tessera: Discretizing Data Analysis Workflows on a Task Level
Jing Nathan Yan, Ziwei Gu, Jeffrey M Rzeszotarski
CHI 2021
paper / video / slides

Interaction logs are useful but can be extremely complex. We break down event logs into goal-directed segments to make it easier to understand user workflow.

Understanding User Sensemaking in Machine Learning Fairness Assessment Systems
Ziwei Gu*, Jing Nathan Yan*, Jeffrey M Rzeszotarski (*equal contribution)
WWW 2021
paper / video / slides

How do core design elements of debiasing systems shape how people reason about biases? We find distinctive sensemaking patterns for different systems through a think-aloud study.

Silva: Interactively Assessing Machine Learning Fairness Using Causality
Jing Nathan Yan, Ziwei Gu, Hubert Lin, Jeffrey M Rzeszotarski
CHI 2020
paper / short video / long video / slides

We present Silva, an interactive tool that utilizes a causal graph linked with quantitative metrics to help people find and reason about sources of biases in datasets and machine learning models.