Congratulations to Dr. William Su!

VACLab-er William Su successfully defended his dissertation in Spring 2025 and officially graduated with his PhD in May of that year. His dissertation, titled “Understanding How to Improve Data Preprocessing Transparency Through Visualization,” addresses a critical yet frequently overlooked stage of the data science pipeline: how analysts can better understand and reason about the impact of data preprocessing decisions.

More specifically, Dr. Su’s research starts from the observation that while much of the existing work on bias in data science has focused on models, the training data produced during preprocessing can have an equally significant influence on results. To explore this gap, Dr. Su conducted a user study with data scientists and compared his findings to a literature survey of existing preprocessing tools, identifying key discrepancies between current practice and the state of the art. Those findings motivated the design and development of the Preprocess Analyzer (PPA), a new tool built to integrate directly into existing data science work environments and provide users with deeper insight into their preprocessing workflows. A follow-up user study found that compared to existing popular tools, data scientists gained a stronger understanding of their preprocessing workflow when using PPA. Participants highlighted the tool’s ability to surface useful statistics quickly, flag areas of concern, and fit naturally into familiar working environments.

Dr. Su has begun a new role as a Data Scientist at IBM, where he will bring his expertise in visualization and data transparency to challenges in industry.

Congratulations to the newest VACLab alumnus, Dr. William Su!