[Apologies for multiple postings]

*    CS/GRAND Seminar
*    Tuesday, Feb 17, 2008. 2:00 pm
*    Room 430A ST2

Lifelines2: Interactive Visualization of Temporal Categorical Data


Taowei David Wang
Ph.D candidate
Department of Computer Science
University of Maryland, College Park


As large data repositories of temporal data become more prevalent today,
it also becomes more important to develop appropriate techniques to
support visual exploratory tasks on this type of data. Although much
work has been done to develop techniques for numerical time series,
temporal categorical data has been mostly overlooked. This type of data
is best characterized by events that have names and time stamps. To be
able to study the ordering of events and the prevalence of ordering can
reveal interesting relationships among the different events, and
consequently help analysts formulate new hypotheses, gain new insights.
I present Lifelines2, an interactive visualization system designed for
visual analysis of temporal categorical data across multiple records.

At the center of Lifelines2 is the Align-Rank-Filter (ARF) framework. It
allows users to quickly manipulate how they see the data by their
features. Alignment lets users specify a reference event, and
subsequently change the view of data to be relative to that event. This
facilitates the discovery of important temporal relationships associated
with the reference events. Rank and Filter are old ideas that let users
reorder and trim the data. Coupled with alignment, however, they also
offer new affordances to support more sophisticated exploratory tasks.

In this talk, I present the features of Lifelines2, and show a video on
how a medical researcher might use Lifelines2 to identify patients who
exhibit a certain pattern of medical events. I will also present the
results from our controlled study, which shows that the alignment
feature is instrumental in aiding users to perform complex tasks.
Finally, I will talk about the first impressions of Lifelines2 from our
collaborators, and peek at our future research on the topic.

*Short Bio*

Taowei David Wang is a Ph.D candidate in the Department of Computer
Science in the University of Maryland. He is part of the Human Computer
Interaction Lab, and is advised by Ben Shneiderman. His dissertation
topic is on interactive visualization techniques of temporal categorical
data for the purpose of hypothesis generation. He is currently working
closely with physicians and clinicians on searches over electronic
health records for this purpose, and is scheduled to graduate in the
winter of 2009.

Jyh-Ming Lien
Assistant Professor
Department of Computer Science       [log in to unmask]
George Mason University, MSN 4A5
Fairfax, VA, 22030, USA              tel: +1-703-993-9546