Portrait of John Langford

John Langford

Principal Researcher

About

John Langford studied Physics and Computer Science at the California Institute of Technology, earning a double bachelor’s degree in 1997, and received his Ph.D. from Carnegie Mellon University in 2002. Since then, he has worked at Yahoo!, Toyota Technological Institute, and IBM‘s Watson Research Center. He is also the primary author of the popular Machine Learning weblog, hunch.net and the principle developer of Vowpal Wabbit. Previous research projects include Isomap, Captcha, Learning Reductions, Cover Trees, and Contextual Bandit learning.

Projects

Virtual Algorithms Center (VIRAL)

Established: December 27, 2013

MSR has a strong group of scientists working on algorithm design, analysis, and experimental evaluation, as well as researchers in related areas (e.g., coding theory), but no formal algorithms group. The Virtual Algorithms Center (VIRAL) brings these individuals together. The goals of the center is to enhance collaboration between algorithms researchers and the rest of MSR, provide internal consulting, and give an external view of the algorithms research at MSR.

Multiworld Testing

Established: November 1, 2013

Exponentially better than A/B testing. Multiworld Testing (MWT) is the capability to test and optimize over K policies (context-based decision rules) using an amount of data and computation that scales logarithmically in K, without necessarily knowing these policies before or during data collection. MWT can answer exponentially more detailed questions compared to traditional A/B testing. The underlying machine learning methodology draws on research on "contextual bandits" and "counterfactual evaluation".…

Explore-Exploit Learning @MSR-NYC

Established: October 24, 2013

This is an umbrella project for machine learning with explore-exploit tradeoff: the trade-off between acquiring and using information. This is a mature, yet very active, research area studied in Machine Learning, Theoretical Computer Science, Operations Research, and Economics. Much of our activity focuses on "multi-armed bandits" and "contextual bandits", relatively simple and yet very powerful models for explore-exploit tradeoff. We are located in (or heavily collaborating with) Microsoft Research New York City. Most of us are…

Publications

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Projects

Link description

Vowpal Wabbit Future Plans

Date

August 29, 2014

Speakers

Hal Daumé III and John Langford

Affiliation

Microsoft Research New York, University of Maryland

Link description

Panel: Can Projects Coordinate?

Date

August 29, 2014

Speakers

Bart van Merrienboer, Bob Carpenter, Chih-Jen Lin, Frederic Bastien, Hal Daumé III, Heiko Strathmann, John Langford, Koray Kavukcuoglu, Leon Bottou, Nicolas Vasilache, and Sumit Chopra

Link description

Vowpal Wabbit

Date

August 29, 2014

Speakers

Hal Daumé III and John Langford

Affiliation

Microsoft Research New York, University of Maryland

Link description

Introduction and Liblinear

Date

August 29, 2014

Speakers

Chih-Jen Lin and John Langford

Affiliation

Microsoft Research New York, National Taiwan University