Carnegie Mellon University

Roni Rosenfeld

Roni Rosenfeld

Professor, Machine Learning, Language Technologies, Computer Science, and Computational Biology

Download Hi-res Photo
Carnegie Mellon University, Gates Center for Computer Science, MLD, 8th Floor, Room 8001
4902 Forbes Ave, Pittsburgh, PA, 15213, USA
Assistant: Christy Melucci, GHC 8009


Roni Rosenfeld (BSc, mathematics and physics, Tel-Aviv University; PhD, computer science, Carnegie Mellon University) is a professor of machine learning, language technologies, computer science, and computational biology in the School of Computer Science at Carnegie Mellon University, Pittsburgh, Pennsylvania. He has taught machine learning and statistical language modeling to thousands of undergraduate and graduate students since 1997, and has been a mentor to five post-doctoral students and an advisor to a dozen PhD students and many Masters and undergraduate students. From 2018 till 2024, he served as head of the machine learning department.

Roni’s current research interests are in tracking and forecasting epidemics. The Delphi research group, which he co-founded and co-leads since 2012, has been playing a leading role in the development of epidemic forecasting technology in the U.S., and has been named a National Center for Epidemic Forecasting by the U.S. CDC.

Roni has previously worked in statistical language modeling, speech recognition, human machine speech interfaces, and the use of speech and language technologies to aid international developments. He has published some 150 scientific articles in academic journals and peer reviewed conferences, is a recipient of the Spira Teaching Excellence Award (2017), and twice the recipient of the Allen Newell Medal for Research Excellence (1992, 2022).


PhD, Computer Science, Carnegie Mellon University, School of Computer Science, Pittsburgh, PA, United States • 1994

MSc, Computer Science, Carnegie Mellon University, School of Computer Science, Pittsburgh, PA, United States • 1991

BSc, Mathematics and Physics, Tel Aviv University, Tel Aviv, Israel1985



Forecasting Epidemics: The long term vision of our Delphi research group is to make epidemiological forecasting as universally accepted and useful as weather forecasting is today. As was the case with weather forecasting, this will likely take a long time. In the shorter term, we select high value epidemiological forecasting targets (currently Influenza and Dengue); create baseline forecasting methods for them; establish metrics for measuring and tracking forecasting accuracy; estimate the limits of forecastability for each target; and identify new sources of data that could be helpful to the forecasting goal.

Past (no longer accepting students):

Information and Communication Technologies for Development (ICT4D), and specifically Spoken Language Technologies for Development (SLT4D), which is the term we coined for our own subfield of ICT4D: finding ways to use spoken language technologies (like automatic speech recognition, speech synthesis, and human-machine dialog systems) to aid socio-economic development around the world.

Machine Learning for Social Good (ML4SG): We continuously seek problems in non-profits and government organizations, domestically and abroad, which can benefit from machine learning solutions, and match them with suitable teams of students and supervising faculty. If your organization could use free machine learning or data science expertise to help improve its societal impact, please contact us. Best cases are those where the potential for societal impact is evident, the questions are well defined, and significant relevant data is available. Otherwise, we can work with you to get your problem ready for our students. This initiative is now overseen by Prof. Rayid Ghani.

Data Numeracy for All: I believe that universal data numeracy is as important in the 21st century as universal literacy was in the 20th. We need to increase the understanding of (and comfort with) data in all segments of society. I am interested in devising effective ways of doing that.undefinedundefined


All publications, including:

  • Computational Epidemiology and Computational Biology
  • Spoken Language Technologies for Development
  • Human-Machine Speech Communication
  • Statistical/Machine Learning Methods in Speech and Language Processing

Current postdocs and students

Aaron Rumack

MLD, Postdoc, Epi-forecasting

Aaron Rumack

Jingjing Tang

CompBio, Epi-forecasting

Jingjing Tang

Ananya Joshi

CSD, Epi-forecasting

Ananya Joshi

Ruiqi Lyu

CompBio, Epi-forecasting

Ruiqi Lyu

Graduated PhD students

Aaron Rumack (MLD, Epi-forecasting)
Logan Brooks (CSD, MLD, Epi-forecasting)
David Farrow (CompBio, viral evolution + Epi-forecasting)
Ali Raza (LTI, ICT4D)
Chuang Wu (CompBio, viral genotype-phenotype mapping)
Jahanzeb Sherwani (CSD, ICT4D)
Yong Lu (CSD, CompBio)
Dan Bohus (CSD, dialog systems)
Stefanie Tomko (LTI, speech communication)
Jerry (Xiaojin) Zhu (LTI, MLD, semi-supervised learning)
Lin Chase (RI, speech recognition)

Past postdocs

Logan Brooks (Epi-forecasting)
Andy Walsh (computational virology)
Xiaojin Wang (machine learning)
Stan F. Chen (language modeling)
Pierre DuPont (language modeling)

My Favorite Quotes:

Indulge your passion for science, says [Nature], but let your science be human, and such as may have a direct reference to action and society. Abstruse thought and profound researches I prohibit, and will severely punish, by the pensive melancholy which they introduce, by the endless uncertainty in which they involve you, and by the cold reception which your pretended discoveries shall meet with, when communicated.  Be a philosopher; but, amidst all your philosophy, be still a man.
-- David Hume

The only thing necessary for the triumph of evil is for good people to do nothing.
-- Edmund Burke, 1776

As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life -- so I became a scientist.  This is like becoming an archbishop so you can meet girls.
-- Matt Cartmill

The life of man is but a succession of vain hopes and groundless fears.
-- Baron de Montesquieu

Believers in supernatural dogma of all sorts accept, without a shred of objective evidence, comprehensive propositions about the universe, our place in it, and how we should relate to one another.
-- Jeffrey Tayler

Nobody on their deathbed has ever said "I wish I had spent more time at the office".
 -- Heard from Rabbi Harold Kushner; Attributed by some to Senator Paul Tsongas.
The whole entire world is a very narrow bridge. 
But the main thing to recall, is to have no fear at all.
-- Rabbi Nachman of Breslav

Who has not found the Heaven - below -
Will fail of it above -
For Angels rent the House next ours,
Wherever we remove
 -- Emily Dickinson

When they turn the pages of history,
When these days have passed long ago,
Will they read of us with sadness
For the seeds that we let grow?
 -- Neil Peart

There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.

There is another which states that this has already happened.
-- Douglas Adams, "The restaurant at the end of the universe"


To laugh often and much; to win the respect of intelligent people and the affection of children; to earn the appreciation of honest critics and endure the betrayal of false friends; to appreciate beauty; to find the best in others; to leave the world a bit better, whether by a healthy child, a garden patch or a redeemed social condition; to know even one life has breathed easier because you have lived.  This is to have succeeded.
-- Ralph Waldo Emerson

 If I could live my life again
 in the next one I would try to make more mistakes
 I would not try to be so perfect, I would relax more.
 I would be more dumb than I have been, in fact
 I would take very few things seriously.
 I would be less hygienic.
 I would take more risks, more trips,
 I would watch more sunsets,
 I would climb more mountains, swim more rivers.
 I would go to places where I have never been to,
 I would eat more ice-cream and less beans,
 I would have more real problems and less imaginary ones.
 I was one of those people who live sensibly and
 prolifically every minute of their life.
 Of course I had happy moments. But if I could
 go back I would try to have only happy moments.
 In case you didn't know life is is made of that, of
 moments only; don't waste this very minute.
 I was one of those people who never went anywhere without
 a thermometer, a bag of hot water, an umbrella and
 a parachute; if I could live again, I would travel light.
 If I could live again I would start to walk barefoot
 at the beginning of the Spring and stay like that until the end
 of the Fall. I would go around more on the calash, I would contemplate more
 dawns and I would play with more children, if I had again life

But, you see, I am 85 years old and I know I am dying.
 -- J. L. Borges