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EventFlow: Exploring Point and Interval Event Temporal Patterns

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Project Description

The HCIL's ongoing work with temporal event records has produced powerful tools for analyzing and exploring patterns of point-based events (Lifelines2, LifeFlow). However, users found that point-based events limited their capacity to solve problems that had inherently interval attributes, for example, the 3-month interval during which patients took a medication. To address this issue, EventFlow extends its predecessors to support both point-based and interval-based events. Interval-based events represent a fundamental increase in complexity at every level of the application, from the input and data structure to the eventual questions that a user might ask of the data. Our goal was to accomplish this integration in a way that appeared to users as a simple and intuitive extension of the original LifeFlow tool. With EventFlow, we present novel solutions for displaying interval events, simplifying their visual impact, and incorporating them into meaningful queries.


  • Megan Monroe, PhD Candidate, Computer Science
  • Sana Malik, PhD Candidate, Computer Science
  • Fan Du , PhD Candidate, Computer Science
  • Christopher Imbriano , PhD Candidate, Computer Science
  • Catherine Plaisant, Research Scientist, UMIACS
  • Ben Shneiderman, Professor, Computer Science
  • Jeff Millstein, Oracle Research
  • Past Participants
  • Rongjian Lan, PhD Candidate, Computer Science
  • Krist Wongsuphasawat PhD, Computer Science
  • Sigfried Gold, Social & Scientific Systems
  • Collaborators
  • We appreciate the collaboration of clinical researchers and epidemiologists at the US Army Pharmacovigilance Center, University of Maryland School of Pharmacy, National Children Hospital, University of Florida, Washington Hospital Center, and many others.



We appreciate the partial support of Oracle Corporation, The Center for Health-related Informatics and Bioimaging (CHIB) at the University of Maryland, the Maryland Industrial Partnerships (MIPS) program and Pulse8. EventFlow builds on early work (LifeLines2 and LifeFlow) which was funded in part by NIH - National Cancer Institute grant RC1-CA147489, Interactive Exploration of Temporal Patterns in Electronic Health Records.


If you are in a rush, this video provides a good overview of how the EventFlow aggregation is constructed, and how the search and replace can be used to manipulate the data to answer questions.

Or: take a look at the analysis of BASKETBALL data:

Basketball Play-by-play Analysis

The Offensive Rebounding of the Indiana Pacers

OR see an OLDER demo but still useful because it stats with a different example dataset (exploring patient paths after they enter the Emergency Room - e.g. looking for bounce back)


The following slides provide an introduction to the motivation behind EventFlow, and a summary of its features. A full description can be found in the tech report.

Other Presentations

Temporal Event Querying - Presented at CHI2013
Dataset Simplification - Presented at MedStar 2/13
Basketball Play-by-play Analysis - Presented at the 2013 HCIL Symposium


EventFlow is still under development, so we have not made the software publicly available yet. However, if you have data that you would like to analyze with EventFlow, please contact with a description of your project and we will share EventFlow with you in exchange for your feedback.

User Support

Users can refer to the EventFlow Manual, which covers all the major features of EventFLow.

To learn more about the EventFlow data format, go to the EventFlow data format section in the user manual.

To generate datasets for testing, use the Dataset Generator.

The (now old) 2012 scalability report, which provides suggestions for dealing with large datasets.

Users can also participate in our EventFlow User Group Meeting to share their experiences using EventFlow, and ideas for potential improvements.


SHORT PAPER TO GET STARTED: A case study of our collaboration effort with the US Army Pharmacovigilance Center
Megan Monroe, Tamra Meyer, Catherine Plaisant, Rongjian Lan, Krist Wongsuphasawat, Trinka Coster, Sigfried Gold, Jeff Millstein, Ben Shneiderman
A Pilot Study of Asthma Medications in the Military Health System
(Short version accepted at VAHC 2013 workshop)

Another case study short paper
Carter, E., Burd, R., Monroe, M., Plaisant, C., Shneiderman, B.
Using EventFlow to Analyze Task Performance During Trauma Resuscitation
Proc. of the Workshop on Interactive Systems in Healthcare, WISH2013 (2013)

[GOOD REFERENCE] VAST2013 paper describing EventFlow and the simplification of temporal event sequences
Megan Monroe, Rongjian Lan, Catherine Plaisant, Ben Shneiderman
Temporal Event Sequence Simplification
Proceedings of IEEE VAST 2013 Conference.

[GOOD REFERENCE] CHI 2013 Paper on EventFlow's interactive query approach
Megan Monroe, Rongjian Lan, Juan Morales del Olmo, Catherine Plaisant, Ben Shneiderman, and Jeff Millstein
The challenges of specifying intervals and absences in temporal queries:A graphical language approach.
Proceedings of the SIGCHI Conference on Human Factors in Computing Systems 2013

Our latest work on temporal query processing algorithms
Megan Monroe, Amol Deshpande
An Integer Programming Approach to Temporal Pattern Matching Queries

Unpublished Tech Report: early work on temporal event sequence search and replace
Rongjian Lan, Hanseung Lee, Megan Monroe, Allan Fong, Catherine Plaisant, Ben Shneiderman
Temporal Search and Replace: An Interactive Tool for the Analysis of Temporal Event Sequences

Unpublished Tech Report: Early report on extending the Lifeflow overview visualization to handle interval data
Megan Monroe, Krist Wongsuphasawat, Catherine Plaisant, Ben Shneiderman, Jeff Millstein and Sigfried Gold
Exploring Point and Interval Event Patterns: Display Methods and Interactive Visual Query

Other publications written by our case study partners

E. Onukwugha, Y. Kwok, C. Yong, C. Mullins, B. Seal, A. Hussain,
Variation in the length of radiation therapy among men diagnosed with Incident Metastatic Prostate Cancer"
Poster presented at the 2013 ASTRO (American Society for Radiation Ocology)meeting.

Products and papers stimulated by this work

Our original research on LifeFlow and EventFlow stimulated new work by other labs, such as:

  • OutFlow and CareFlow at IBM.
  • Visualizing Uncertain Critical Paths in Schedule Management, by Robert Gove, Brandon Herzog (see VAST 2013 Industry posters)

  • Related HCIL projects and events

    Links of all HCIL Projects related to Temporal Visualization:   LifeLines, LifeLines2, PatternFinder, LifeFlow, etc.

    HCIL EHR Informatics Workshop 2013:   Thursday, May 23, 2013

    EventFlow: User Group Meeting:   Tuesday, November 20, 2012

    HCIL EHR Informatics Workshop 2012:   Wednesday, May 23, 2012