Aleszu Bajak

A senior data reporter at USA TODAY.

Writing        Code and Design        Speaking Engagements        Teaching        Fellowships & Awards        Publications

Aleszu Bajak is a senior data reporter on USA TODAY's data team, part of the newspaper's national investigative unit. He is a former Knight Science Journalism Fellow at M.I.T., was a founding senior writer at Undark magazine and founding editor of Esquire Classic, a project resuscitating the magazine's archives. His work has appeared in The New York Times, The Washington Post, M.I.T. Technology Review and Nature.

Before USA TODAY, he spent several years teaching and managing the graduate programs at Northeastern University's School of Journalism where he launched, an under the hood guide to digital and data storytelling. He's also the founder of, a resource for science news and opinion out of Latin America, which he started in Argentina in 2012.

In 2013, Aleszu was awarded a Knight Science Journalism Fellowship at M.I.T. where he explored the interface between journalists, designers and developers between visits to the Muddy Charles. Since then, he has taught journalism courses and led workshops at the Nieman Foundation for Journalism at Harvard, Brandeis University, Harvard Extension School, Boston University's Storytelling with Data bootcamp, and O'Reilly Media. He has spoken at conferences in Seoul, Toulouse, San Antonio, Bogotá and Querétaro.

He has been a freelance reporter in Latin America, a producer for the public radio show Science Friday, and once upon a time worked in the gene therapy department at Weill Cornell. His writing has appeared in The New York Times, The Washington Post, The Boston Globe Magazine, M.I.T. Technology Review, OjoPúblico, The Huffington Post, Esquire, Nature, Science, and Guernica, among other outlets. He grew up in New Jersey, Germany and Colombia and has lived in Chile, Peru and Argentina. He can be reached at firstname lastname at

Code and Design

Network analysis

Twitter analysis of reactions to the Chauvin verdict

When Derek Chauvin was found guilty for the murder of George Floyd, the verdict spread quickly on social media. We analyzed the volume and rhetoric of social media reactions to the conviction based on a panel of 250 influential accounts on the left and right. Read more at: "The words Americans used after Chauvin verdict reveal our political divide."

Twitter analysis of preprint studies

On May 14, 2020, Jeff Howe and I published "A Study Said Covid Wasn’t That Deadly. The Right Seized It." in The New York Times, which was based on our analysis of how ~900 preprint studies were shared on Twitter. I worked with the Times's Stuart Thompson and Yaryna Serkez to develop a timeline bubble plot and two network visualizations.


How critical race theory became a conservative battle cry

To explore the weaponization of "critical race theory" for USA TODAY, I analyzed and visualized the phrase's evolution from conservative think tanks and blogs through right-wing media and into the mainstream.

A dashboard exploring 29 million tweets related to Covid-19

I built an interactive app and published a report with researchers at Northeastern University's Lazer Lab to explore the top links, domains and keywords extracted from 29 million tweets related to Covid-19 shared between January 1st and September 30th, 2020 by over half a million Americans for whom we had demographic information such as age, state of residence and political party registration.

A data-driven guide to the census’s impact on funding to states

Ahead of the 2020 decennial census, I wrote, designed and managed an ambitious project for Journalist’s Resource at Harvard’s Shorenstein Center that produced a set of downloadable and customizable national, state, regional and program-specific datasets and embeddable data visualizations on census-derived federally funded programs built for newsrooms across the country. Shoutouts to Tyler Machado, John Wihbey and Carmen Nobel for guidance and bottomless patience.

Sentiment Analysis

My analysis of Parler on Jan. 6 found calls for civil war intensified on the right-leaning social media app as Donald Trump urged his followers to march on the Capitol. The article, When Trump started his speech before the Capitol riot, talk on Parler turned to civil war, was cited in Trump's second impeachment trial by Congresswoman Diana DeGette.

My analysis of gender and bias in media coverage of the 2020 Democratic candidates, a collaboration with Northeastern student Alex Frandsen, was picked up by CNN, The New York Times, The Washington Post and more.

With Floris Wu, I published a story at Roll Call exploring the sentiment of politicians on Twitter in the lead-up to the 2018 midterms.

Democrats ‘went low’ on Twitter leading up to 2018

For the 2018 midterm elections, I explored nearly 94,000 Facebook ads collected by ProPublica and compared the sentiment and frequency of ads mentioning Beto O'Rourke or Ted Cruz. Code and visualizations here. Here's a course I taught with Northeastern political science chair Costas Panagopoulos on the 2018 midterms. That course was reprised for the 2020 election.


For Peruvian investigative news outlet OjoPúblico, I collected, geocoded and designed a map of Covid-19 clinical trials with Martin Frigaard.

With the Dakota Access Pipeline protests in North Dakota in full swing, I decided to highlight the actual risk of the pipeline rupturing together with just how pockmarked America's recent track record of spills is. The result, pubished in Undark, was an interactive map based on statistical analysis of federal data - complemented by several in-depth interviews and case studies - of the crude oil pipeline spills America has witnessed in the last decade. Methodology here.

Oil and Water: The Dakota Access Pipeline

For Undark magazine, I built an interactive map showing two decades of deforestation in Nicaragua.

For Undark, I built a series of maps highlighting the American South's vulnerability to the novel coronavirus pandemic.

Topic Modeling

In November 2019, I performed a topic analysis of ~10,000 news articles on the 2020 Democratic candidates with colleagues at Northeastern's School of Journalism, revealing that political coverage, at least this cycle, tracks with the ebbs and flows of scandals, viral moments and news items. Full article and code here.

Using R's topicmodels and quanteda packages, I attempted to predict news topics from the headlines of 10,000 top-performing news articles written between Nov. 2016 and May 2017 and downloaded from NewsWhip. Full methodology and code here.


To better communicate the risk COVID-19 poses in children, USA TODAY's Janie Haseman and I analyzed trends in pediatric flu and COVID hospitalizations, publishing How COVID-19 in kids compares to the flu, other viruses in children along with several graphics.

For Medium's GEN magazine, I wrote about and visualized Twitter attacks on Joe Biden and Elizabeth Warren using data from natural language processing startup MarvelousAI.

I've been using Principal Component Analysis and other NLP techniques in my research at Northeastern's School of Journalism.

For Esquire, I compared the value generated by Martin Scorcese's use of two different actors.



Social media

When Trump started his speech before the Capitol riot, talk on Parler turned to civil war

How the antifa conspiracy theory traveled from the fringe to the floor of Congress


The words Americans used after Chauvin verdict reveal our political divide

How critical race theory went from conservative battle cry to mainstream powder keg


Could we save lives by assigning each American a place in line for vaccines?

Michigan bet big on mass vaccine events for COVID-19. It didn’t work out as hoped.

Did America’s schools open safely? We crunched the latest data on COVID-19 and kids.

How COVID-19 in kids compares to the flu, other viruses in children

COVID and kids: How the omicron surge is impacting child hospitalizations, school safety

‘We’re Apollo 13-ing this vaccine rollout’: Despite years of budget cuts, minuscule staff and constantly escalating demands, health officials pulled off the COVID-19 vaccine rollout.

'Just not equal at all': Vaccine rollout in Chicago a microcosm of racial disparities nationwide


A national system to prioritize COVID-19 vaccines has largely failed as states rely on their own systems

The Washington Post

Her Brain Tormented Her, and Doctors Could Not Understand Why

Someone Is Tracking How Much You Vape on Twitter

What Does Twitter Say About Your Diet?


What should Peru do to improve its science?

Science in Colombia on the cusp of change

Chile’s chance to embrace science for the twenty-first century

Chile’s Scientists Take to the Streets

Argentina: The RNA Sleuths

U.S. Assesses Virus of the Caribbean

Key Galapagos Research Station in Trouble


Microbe new to science found in self-fermented beer

Colombian coffee science

Lectures aren’t just boring, they’re ineffective, too

Abundant natural gas may do little to reduce U.S. emissions


Tratar el Covid-19: separar el entusiasmo de la evidencia. Read it in English here.

The Boston Globe Magazine

Why Trump's talking points become ours. Like it or not.


Climate reporting

For Bordeaux’s Winemakers, Rising Temperatures Bring a Reckoning. Republished at The Atlantic as Global Warming Could Throw France’s Wine-Making Traditions Into Chaos.

Climate Data for the Masses

Rebuilding Louisiana’s Disappearing Delta

To Feed Energy Demand, There Will Be Sprawl

For the Obama Administration, the Clean Coal Dream Lives On

Rushing Climate Science

21st Century Policing

In Police Body Camera Footage, Tech Companies See a Niche

Breaking Down "Broken Windows"

The 2016 Presidential Election

Can Donald Trump Dismantle the EPA? It’s Been Tried Before

Mobilizing Green Latinos

Hillary Clinton and the Cultural Biases of Being ‘Presidential’

Micro-targeting and the 2016 Election

Growing West Virginia’s solar sector?

The Zika Epidemic

Changing Latin America's Culture of Insular Science

Playing Politics With Zika — and the Public’s Health

The Blind Pursuit of Mosquito Control

For the U.S., a More Worrisome Zika Vector?

For Venezuela's Zika Woes, Some Tylenol

While Congress Dithered, the Zika Virus Flourished in Puerto Rico

Maps and Podcasts

Map: The Persistent Scourge of Lead Paint

Podcast: Rebuilding Louisiana’s disappearing delta. Plus, the accompanying article.

Browse all my stories for Undark here.

MIT Technology Review

Will Embryonic Stem Cells Ever Cure Anything?

GEN magazine

Biden and Warren Were the Top Post-Debate Targets on Twitter


The landscape architect turned steward of Colombia's endangered monkey


How to use hierarchical cluster analysis on time series data

How Quartz is bringing storytelling and interactive design to sponsored content

Revolutionizing the work of newsrooms by making citizen videos searchable

How to learn responsive web design by coding your own news article

How to organize your data for various charts and graphs

The Huffington Post

The Dangerous Belief That Extreme Technology Will Fix Climate Change

Craft Beer Brewers Feel Effects Of Climate Change


Boxing in Cuba (book review)

Phil Caputo: What I've Learned

Don Zimmer’s hard head

Frank Sinatra Turns 100

Quiz: Which Tech Titan said it?

Dataviz: Happy Birthday, Martin Scorsese!


Catching fog in Lima

Science Friday

Video: Dean Kamen and the FIRST robotics competition

Video: Counting horseshoe crabs on Long Island

Video: Tending crops on a Brooklyn rooftop

New Scientist

Catcher in the fog


Fossil fuels get a lot more global subsidies than public health does

Failures of Brazil's universal health care plan offer lessons for the US

Ensia magazine

The world is awash in pesticides. Does it have to be?

In Water We Trust

Beeradvocate magazine

What if a hurricane like Sandy hit your brewery?

Should You Be Worried About the BPA in Your Beer Can?

Sequencing Wild Yeast

Unlocking the Science of Hop Aromas

The Lager Yeast Genome Project

Brewing in Thin Air

The Illegal Beer Business

Stemming the Rise of Barley Diseases: How Nasty Fungal Infections Could Affect Our Grains and Beer


Safeguarding biodiversity in tourism hotspots

Represas hidroeléctricas propician extinción de especies

Prevenir pandemias es más barato que combatirlas

Intervención de la comunidad ayuda a prevenir el Chagas

Trunk magazine

Darwin, Neruda and Me

Latin American Science

The future of Latin American science

The dengue detectives

A year later, the effects of a volcanic eruption still plague Patagonia

A farm runs on homemade biodiesel in Argentina

Zócalo Public Square

How can we fight the rise of deadly superbugs?

Back in Colombia – and on the Gringo Trail

Modern Farmer

Colombian coffee at the crossroads

Revista Qué Pasa

Latinoamérica genial

The Specialty Coffee Chronicle

Can the world’s growing appetite for unique coffee save Brazil’s specialty coffee farms?

Christian Science Monitor

São Paulo razes crack cocaine shantytown


Speaking engagements, workshops

National Press Foundation "How Data Journalists Track Politics" panel, Winter, 2022.
ESRI Latin America presentation on mapping in journalism, Fall, 2021.
O'Reilly course on Text Mining and Sentiment Analysis in R, Fall, 2019.
Newsroom Textual Analysis and Visualization Tools Built With R Shiny, Computation plus Journalism conference, Miami, 2019
Mapping for environmental reporting, European Conference of Science Journalists, Toulouse, France, 2018
Global Resilience Institute Flash Talk, Northeastern University, 2018
Urban Tensions hackathon, Northeastern University, 2017
Covering Housing workshop, Nieman Foundation, 2017
Communicating ciencia, National Association of Science Writers conference, San Antonio, Texas, 2016
So you want to be a data journalist?, CUNY Graduate School of Journalism, 2016
Intro to data visualization workshop, Nieman Foundation, 2016
Iberoamerican conference on science journalism, Digital frontiers keynote talk, Mexico, 2015
Power of Narrative conference panel on digital journlism and seminar on Latin American science, Boston University, 2015
Storytelling with Data workshop on data visualization tools, Boston University, 2015
World Conference of Science Journalists panel on Latin American science, Seoul, South Korea, 2015
Ciencia y periodismo (Science and Journalism), Nexos Chile-USA keynote talk, Harvard University D.R.C.L.A.S., 2015
Digital cartography workshop, Nieman Foundation, 2015




Fall 2019
Digital Storytelling and Social Media, Northeastern Journalism School
Spring 2019
Science Writing, Northeastern Journalism School
Fall 2018
Midterm Mayhem, Northeastern University (with Costas Panagopoulos)
Fall 2018
Digital Storytelling and Social Media, Northeastern Journalism School
Spring 2018
Digital Storytelling and Social Media, Northeastern Journalism School
Fall 2017
Digital Storytelling and Social Media, Northeastern Journalism School
Fall 2016
Nieman Digital Storytelling, Nieman Foundation
Fall 2016
Fundamentals of Digital Journalism, Northeastern Journalism School
Spring 2016
Science and Journalism in Society, Brandeis University
Fall 2015
Media Innovation Studio, Northeastern Journalism School
Spring 2015
StoryLab: Reinventing Magazine Journalism, Northeastern Journalism School (with David Tames)
Summer 2014
Foreign Correspondence in the Digital Age, Harvard Extension School


Fellowships & Awards

Data Journalism Awards, shortlist for best data journalism website,, 2019
Knight Science Journalism Fellow, M.I.T., 2013—2014
Ocean Science Fellow, Woods Hole Oceanographic Institution, September, 2014
Information is Beautiful Award, shortlist for best data visualization website,, 2015
Best magazine writing, North American Guild of Beer Writers
Sequencing Wild Yeast, 1st place, 2016
Unlocking the Science of Hop Aromas, 1st place, 2015
Stemming the Rise of Barley Disease, 3rd place, 2014
Brewing in Thin Air, 3rd place, 2013




COVID-19 Fake News on Twitter, Lazer, Ruck, Quintana, Shugars, Joseph, Grinberg, Gallagher, Horgan, Gitomer, Bajak, Baum, Ognyanova, Qu, Hobbs, McCabe and Green. The COVID-19 Consortium for Understanding the Public’s Policy Preferences Across States.

Source Attribution: Recovering the Press Releases Behind Health Science News, MacLaughlin, A., Wihbey, J., Bajak, A., Smith, D. 2020. ICWSM Proceedings 2020.

CómoSciWri: Resources to help science writers engage bicultural and bilingual audiences in the United States, Landis, B., Bajak, A., de la Hoz, J., González, J., Gose, R., Tibbs, C., Oskin, B. 2020. Frontiers in Communication.

A Prototype Machine Learning and Data Visualization Platform for Text Classification, Annis, J. Sheth, D., Bajak, A. 2020. Computation + Journalism Symposium, Northeastern University.

Newsroom Textual Analysis and Visualization Tools Built With R Shiny, Bajak, A., Wihbey, J., Free, G., Merten, P. 2019. Computation + Journalism Symposium, University of Miami.

Funding the News: Foundations and Nonprofit Media Nisbet, M., Wihbey, J., Kristiansen, S., Bajak, A. 2018. Shorenstein Center.

Collaborative, Open, Mobile: A Thematic Exploration of Best Practices at the Forefront of Digital Journalism, Howe, J., Bajak, A., Kraft, D., and Wihbey, J. 2017. Working paper.