John Alexis
Guerra Gómez

I do Visual Analytics, i.e., I include the user in the big data analysis/science loop.

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In a nutshell

Information Visualization Researcher and Engineer. I help people extract insights from their data using interactive infovis and data science. PhD in Computer Science, Assistant Teaching Professor at Northeastern University Bay Area. I conduct research on Visual Analytics, Accessibility, Big data, Human Computer Interaction and Web Development. Formerly at UCBerkeley, Uniandes Colombia, Yahoo Labs, Xerox PARC and DUTO .


My Skills

My Skils

The tools and techniques I use

What tools I use

Experience and Education

08/2020 to Present
Assistant Teaching Professor
  • Conducting research in information visualization and accesibility.
  • Teaching: Web Development, Database Management Systems and Information Visualization.

06/2016 to 06/2020
Assistant Professor (Tenure Track)

01/2017 to 06/2020
Remote Lecturer and Course Coordinator

Yahoo Labs
01/2015 to 04/2016
Postdoctoral Researcher
  • Explored information visualization interfaces for navigating big repositories of photos.
  • Helped redesign Flickr stats.
  • Developed and deployed a visualization for better exploring the organizational units that is being used company wide.
  • Modified Flickr code to add a new photo navigation visualization.
  • Four papers accepted in two major conferences (CHI2016 and AVI2016).
  • Created visual analytics for dozens of complex Yahoo datasets.

05/2013 to 12/2014
Research Scientist
  • Created Network Explorer a visual network analytics tool to explore hundreds of thousands of nodes, which was implemented, among others, in a Fraud, Waste and Abuse solution from Xerox and is being used for detecting fraud in Health Care networks.
  • Constructed several dashboards using Tableau.
  • Developed and integrated several other time-based and text based visualizations in 3 different products.

Inventor, Entrepreneur, Speaker

08/2008 to 04/2013
PhD Student, RA and TA.
  • PhD and MSc in Computer Science under the supervision of Dr. Ben Shneiderman and Dr. Catherine Plaisant at the University of Maryland (2013).
  • Created the StemView a visualization technique that represents 5 characteristics of change in trees.
  • Created the Bullet a visualization glyph that represents 4 characteristics of change in trees.
  • Implemented TreeVersity2 a visual analytics web application to explore change in datasets over time.
  • Implemented TreeVersity a visual analytics desktop application to compare changes between two trees.
  • Conducted 13 case studies with 9 domain experts to validate TreeVersity and TreeVersity2.

01/2005 to 01/2008
Full Time Lecturer

06/2003 to 06/2013
Co-founder and CTO

Academic contributions

Order by:

Things I have built


A visualization widget that you can use to explore large data


A search engine for tactile images for the blind.


Twitter monitor and analyzer for different topics


Representing groups of photos with numeric attributes. Work in progress, pending publication.

Network Explorer

Network Explorer

Visual analytics tool for understanding large networks. Pending publication.

TreeVersity v2

Visualizing five dimensions of change in a dataset changing over time using hierarchies

TreeVersity v1

Comparing changes between trees on structure and node values.


A visual analytics tool for temporal categorical data. Helped developing the comparison modules as part of a broader project.


A system to allow blind children to see colors and shapes with their hands