Jelani Nelson

Jelani Nelson

  • Associate in Computer Science


Jelani Nelson joined SEAS in 2013. His research focuses on the development of efficient algorithms for massive datasets, especially algorithms that use little memory and require only a single or few passes over the data (so-called “streaming algorithms”). 

Using a technique called "sketching," it is possible to create a very compressed version of a dataset that lacks all the detail but provides sufficient information to answer certain queries. Sometimes, these sketches can be exponentially smaller than the original dataset, allowing savings in processing time, communications bandwidth, and required storage capacity. The algorithms that produce these sketches, however, must be carefully designed to guarantee an adequate degree of accuracy.

Nelson has done research in sketching applied to several areas, including streaming, dimensionality reduction, compressed sensing, and numerical linear algebra. The applications of this work could help improve computational tools in fields like computer vision, machine learning, databases, and data mining.

Contact Information
Assistant:Carol Harlow
Assistant Office:Maxwell Dworkin 343
Assistant Phone:(617) 496-1440

Primary Teaching Area

Positions & Employment

Harvard School of Engineering and Applied Sciences

  • July 2017-onward: Associate Professor of Computer Science
  • July 2017-onward: John L. Loeb Associate Professor of Engineering and Applied Sciences
  • July 2013-June 2017: Assistant Professor of Computer Science

Institute for Advanced Study

  • September 2012-June 2013: Member

Princeton University Center for Computational Intractibility

  • January 2012-September 2012: Postdoctoral Researcher

Mathematical Sciences Research Institute

  • August 2011-December 2011: Postdoctoral Researcher


  • Presidential Early Career Award for Scientists and Engineers (PECASE), 2017
  • Alfred P. Sloan Research Fellow, 2017
  • ONR Director of Research Early Career Award, 2016
  • ONR Young Investigator Award, 2015
  • NSF CAREER award, 2014
  • George M. Sprowls Award, given for the best doctoral theses in computer science at MIT
  • IBM Research Pat Goldberg Memorial Best Paper Award, 2010
  • Best Paper Award, ACM Symposium on Principles of Database Systems (PODS), 2010