PeopleofSuperintelligence

Researcher

Lev Ratinov

Also known as Lev-Arie Ratinov

Lev Ratinov is an AI researcher whose work spans semi-supervised learning, named-entity recognition and word representations. With Ming-Wei Chang and Dan Roth, he publishes constraint-guided learning research in 2007 and named-entity recognition work in 2009. His 2010 word-representations paper with Joseph Turian and Yoshua Bengio shares the ACL Test-of-Time Award in 2020. He earns a computer-science PhD at Illinois in 2012, contributes to CogCompNLP in 2018 and co-invents a patent on detecting keyword-stuffed business titles. As of October 2026, he leads platform technology and security at ClearToStart.

Now at
ClearToStart
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Timeline

  1. 2007–2009

    Constraint learning and NER

    With Ming-Wei Chang and Dan Roth, he coauthors a paper on constraint-driven semi-supervised learning at ACL in 2007. At CoNLL in 2009, he and Roth publish “Design Challenges and Misconceptions in Named Entity Recognition.”

  2. 2010

    Word representations for NLP

    With Joseph Turian and Yoshua Bengio, he publishes “Word Representations: A Simple and General Method for Semi-Supervised Learning” at ACL in 2010.

  3. 2012

    A computer-science PhD

    In 2012, he earns a PhD in computer science from the University of Illinois at Urbana-Champaign, with Dan Roth as his advisor.

  4. 2013

    A Google patent application

    In 2013, he and Baris Yuksel are listed as inventors on an application for detecting keyword-stuffed business titles.

  5. 2015

    The patent is granted

    US9135625B1 is granted in 2015.

  6. 2018

    The CogCompNLP toolkit

    In 2018, he coauthors CogCompNLP, a suite of core libraries and demos for natural language processing developed by the Cognitive Computation Group.

  7. 2020

    An ACL Test-of-Time Award

    In 2020, he shares the ACL Test-of-Time Award with Joseph Turian and Yoshua Bengio for their 2010 word-representations paper.

  8. As of October 2026

    Platform technology and security

    As of October 2026, he leads platform technology and security at ClearToStart.

Career

  1. NowClearToStartPlatform Technology and Security Lead

Education

  1. 2012University of Illinois Urbana-ChampaignPhD in computer science

From the biography.

  1. The Massachusetts Institute of Technology trained or employed 44 of the 187 AI major-prize winners, more than any other universityIncludes University of Illinois Urbana-Champaign. The Massachusetts Institute of Technology trained or employed 44 of the 187 AI major-prize winners, more than any other university. We compare doctorate and 5+ year employment links, career timing and current workplaces for 187 major-prize and 1,111 best-paper winners.
  2. 84% of people shaping AI with recorded undergraduate and doctoral schools changed institutions for their doctorateIncludes University of Illinois Urbana-Champaign. 84% of people shaping AI with recorded undergraduate and doctoral schools changed institutions for their doctorate. Across 2,116 people with both an undergraduate degree and a doctorate recorded, we trace which undergraduate schools feed which doctoral programs, how often students stay at the same school, and how paths differ by birth-country region.
  3. More people shaping AI studied at Massachusetts Institute of Technology than at any other institutionIncludes University of Illinois Urbana-Champaign. 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.
  4. 11% of AI doctorate holders from 2010 to 2016 founded or led a company or lab by 10 years after graduationIncludes University of Illinois Urbana-Champaign. We estimate how often AI doctorate holders founded or led a company or lab by 10 years after graduation, how waiting times compare between founders and top jobs, and which universities trained the most.

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 Lev Ratinov yet. Send us a free-licensed photo.

  1. Guiding Semi-Supervision with Constraint-Driven Learning - ACL Anthology aclanthology.org. Checked 21 October 2026.
  2. Lev Ratinov - ACL Anthology aclanthology.org. Checked 21 October 2026.
  3. Word Representations: A Simple and General Method for Semi-Supervised Learning - ACL Anthology aclanthology.org. Checked 21 October 2026.
  4. Exploiting knowledge in NLP | IDEALS ideals.illinois.edu. Checked 21 October 2026.
  5. US9135625B1 - Systems and methods of detecting keyword-stuffed business titles - Google Patents patents.google.com. Checked 21 October 2026.
  6. CogCompNLP | cogcomp-nlp cogcomp.github.io. Checked 21 October 2026.
  7. ACL Test-of-Time Papers Award Recipients - Admin Wiki aclweb.org. Checked 21 October 2026.
  8. Meet the Team | ClearToStart cleartostart.com. Checked 21 October 2026.