PeopleofSuperintelligence

Researcher

Roni Rosenfeld

Also known as Ronald Rosenfeld, רוני רוזנפלד

Roni Rosenfeld is a Carnegie Mellon machine learning researcher whose work runs from statistical language modeling to epidemic forecasting. After a BSc in mathematics and physics at Tel Aviv University in 1985, he earned a Carnegie Mellon PhD in computer science in 1994 with a thesis on maximum entropy language modeling and joined the faculty there. In 2012 he co-founded the Delphi Research Group, whose flu forecasts use machine learning, and the CDC named Delphi an Influenza Forecasting Center of Excellence in 2019. From 2018 to 2024, he headed the Machine Learning Department, and the CDC funded the Delphi Center for Innovation in Outbreak Analytics and Disease Modeling in 2023. He is University Professor of machine learning, language technologies, computer science and computational biology at Carnegie Mellon and co-leads Delphi.

Born
1959
Works
199
Citations
10,312
h-index
48
Badges

Years link to their sources. Publication numbers from OpenAlex, as of 22 October 2026.

Timeline

  1. 1985–1994

    Tel Aviv to a CMU doctorate

    He earns a BSc in mathematics and physics at Tel Aviv University in 1985 and a PhD in computer science at Carnegie Mellon in 1994. As a graduate student, he develops and open-sources a statistical language-modeling toolkit that lets anyone build language models from their own corpora. In 1992, his work on speech recognition technologies earns him Carnegie Mellon's Allen Newell Award for Research Excellence.

  2. 1994–2001

    Joining CMU and a thesis award

    He joins the faculty of Carnegie Mellon's School of Computer Science as an assistant professor in 1994. In 2001, his thesis on maximum entropy language modeling, advised by Raj Reddy and Xuedong Huang, wins the Computer, Speech and Language award for "Most Influential Paper in the Last 5 Years."

  3. 2012–2017

    Co-founding the Delphi group

    He co-founds the Delphi Research Group at Carnegie Mellon in 2012 with Ryan Tibshirani. Its flu forecasts include a machine-learning method that predicts from past patterns and CDC surveillance data, and in October 2017 its two systems take the top two spots in the 2016-2017 flu forecasting challenge.

  4. 2018–2024

    Heading the Machine Learning Department

    In July 2018, he becomes head of Carnegie Mellon's Machine Learning Department, succeeding Manuela Veloso. He serves as head until 2024.

  5. 2019

    A CDC flu forecasting center

    In 2019, the CDC designates Delphi an Influenza Forecasting Center of Excellence, with $3 million in research funding. Rosenfeld leads the center.

  6. 2020

    COVIDcast tracks COVID-19 symptoms

    Starting in April 2020, Delphi collects real-time data on self-reported COVID-19 symptoms and other disease indicators nationwide. In September 2020, Google.org donates $1 million to Carnegie Mellon to support COVIDcast, the group's effort to track and forecast localized COVID-19 activity.

  7. 2023

    A CDC outbreak analytics center

    In September 2023, the CDC's Center for Forecasting and Outbreak Analytics announces five-year, $17.5 million funding for the Delphi Center for Innovation in Outbreak Analytics and Disease Modeling, one of 13 centers in a national network. Rosenfeld is a co-director of the Delphi Research Group.

  8. As of October 2026

    University Professor at Carnegie Mellon

    He is University Professor of machine learning, language technologies, computer science and computational biology at Carnegie Mellon and co-leads the Delphi Research Group. In February 2026, Sleep Cycle announces a research collaboration with Delphi, with Rosenfeld as principal investigator, to study cough and breathing signals from sleep data for epidemic surveillance.

Career

  1. Since 1994Carnegie Mellon UniversityAssistant Professor, Co-founder and co-lead

Education

  1. 1994Carnegie Mellon UniversityPhD
  2. 1985Tel Aviv UniversityBSc

From the biography and OpenAlex affiliations (the years of papers that list the organization), so some years are approximate.

Most-cited works

  1. Two decades of statistical language modeling: where do we go from here?2000 · Proceedings of the IEEE · 735 citations
  2. Semi-supervised learning with graphs2005 · 636 citationsWith John D. Lafferty
  3. A maximum entropy approach to adaptive statistical language modelling1996 · Computer Speech & Language · 541 citations
  4. Improving Text Classification by Shrinkage in a Hierarchy of Classes2022 · 471 citationsWith Andrew McCallum
  5. Learning Hidden Markov Model Structure for Information Extraction2018 · 381 citations

From OpenAlex, as of 21 October 2026.

  1. More people shaping AI studied at Massachusetts Institute of Technology than at any other institutionIncludes Carnegie Mellon University. We estimate where the people shaping AI studied and where their careers led. Massachusetts Institute of Technology leads with 467 former students, including 291 recorded doctorates.
  2. The company share of AI researchers’ top papers was 31% in 2020–2024 and 8% in 1970–1974Includes Carnegie Mellon University. We estimate where the people shaping AI worked when their most-cited papers appeared: the company share was 31% in 2020–2024 and 8% in 1970–1974, and Google led all organizations in 2020–2024.
  3. Google has the highest combined h-index among AI organizationsIncludes Carnegie Mellon University. We estimate that Google holds the highest combined h-index at 8,016, while universities account for 73% of the deduplicated total across AI organizations.
  4. The median h-index is 48 at universities and 14 at frontier AI labsIncludes Carnegie Mellon University. The median h-index is 48 at universities and 14 at frontier AI labs. We compare publishing careers, recent citations, dual appointments and job moves across 2,420 university researchers and 308 frontier-lab researchers.

Colleagues

People named in this biography, and people with dated positions at the same organization in the same years.

Sources and credits

Photo: We have no published photo of Roni Rosenfeld yet. Send us a free-licensed photo.

  1. Roni Rosenfeld ml.cmu.edu. Checked 20 October 2026.
  2. Roni Rosenfeld - Wikipedia en.wikipedia.org. Checked 20 October 2026.
  3. Carnegie Mellon Names Rosenfeld Head of Machine Learning Department - News - Carnegie Mellon University cmu.edu. Checked 20 October 2026.
  4. Delphi Group Uses Data To Forecast the Flu and Other Epidemics - Statistics & Data Science - Dietrich College of Humanities and Social Sciences - Carnegie Mellon University cmu.edu. Checked 20 October 2026.
  5. Carnegie Mellon Points Flu Forecasting at COVID-19; Outcomes Unknown -- Campus Technology campustechnology.com. Checked 20 October 2026.
  6. CDC Selects Delphi Research Group as Center for Innovation in Outbreak Analytics and Disease Modeling - CMU Ambassadors - Carnegie Mellon University cmu.edu. Checked 20 October 2026.
  7. Sleep Cycle and Carnegie Mellon To Explore Sleep Data To Detect Outbreaks - Inderes inderes.se. Checked 20 October 2026.