Koby Crammer
Koby Crammer is a machine-learning researcher whose work spans margin-based online learning, domain adaptation, natural language processing and cross-task transfer. At the Hebrew University of Jerusalem, he earned a BSc in 1999 and a computer science PhD in 2004, publishing on multiclass kernel machines with Yoram Singer in 2001, and worked from 2004 to 2009 at the University of Pennsylvania, where he gave an ACL-08 tutorial on online learning for NLP. His papers introduced passive-aggressive online algorithms in 2006, confidence-weighted learning in 2008, Gaussian Margin Machines and the AROW algorithm in 2009, semi-supervised sentiment classification on unlabeled Amazon reviews in 2012, and Target-Aware Weighted Training in 2021. Having joined the Department of Electrical Engineering at the Technion – Israel Institute of Technology in 2009, he is affiliated with the Technion as an artificial intelligence researcher as of October 2026.
- Now at
- Technion
Timeline
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1999–2004
Degrees and multiclass kernel machines
At the Hebrew University of Jerusalem, he receives a BSc in mathematics, physics and computer science in 1999 and a PhD in computer science in 2004, both summa cum laude. In 2001, he and Yoram Singer publish On the Algorithmic Implementation of Multiclass Kernel-based Vector Machines, which gives a direct margin-based method for training multiclass predictors with kernels.
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2006
Passive-aggressive online learning
In 2006, he coauthors Online Passive-Aggressive Algorithms with Ofer Dekel, Joseph Keshet, Shai Shalev-Shwartz and Yoram Singer, presenting margin-based online algorithms for binary and multiclass categorization, regression, uniclass prediction and sequence prediction. Also in 2006, he coauthors Analysis of Representations for Domain Adaptation, deriving a generalization bound that illustrates the tradeoffs in designing representations for domain adaptation.
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2008
NLP research at Penn
From 2004 to 2009, he serves as a postdoctoral fellow and research associate in the Department of Computer and Information Science at the University of Pennsylvania, holding a PhD from Hebrew University. In 2008, he gives an ACL-08 tutorial on advanced online learning for natural language processing.
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2008
Confidence-weighted online learning
In 2008, he coauthors Exact Convex Confidence-Weighted Learning with Mark Dredze and Fernando Pereira. The paper derives a convex constraint for online learning with linear classifiers and analyzes it under a mistake-bound model.
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2009
Joining Technion and Gaussian Margin Machines
In 2009, he joins the Department of Electrical Engineering at the Technion – Israel Institute of Technology. In 2009, he also coauthors Gaussian Margin Machines with Mehryar Mohri and Fernando Pereira, maintaining a Gaussian distribution over weight vectors for binary classification, and coauthors Adaptive Regularization of Weight Vectors, introducing the AROW algorithm for online learning under label noise.
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2012
Sentiment from unlabeled reviews
In 2012, he coauthors the appendix to More Is Better: Large Scale Partially-supervised Sentiment Classification with Yoav Haimovitch and Shie Mannor. It describes a bootstrapping algorithm for partially labeled data and tests sentiment classification with up to 15 million unlabeled Amazon product reviews.
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2021
Weighted training across tasks
In 2021, he coauthors Weighted Training for Cross-Task Learning with Shuxiao Chen, Hangfeng He, Dan Roth and Weijie J. Su. Its Target-Aware Weighted Training method minimizes a representation-based distance between source and target tasks.
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As of October 2026
Research at Technion
As of October 2026, he is a researcher in artificial intelligence affiliated with the Technion – Israel Institute of Technology.
Career
- NowTechnionResearcher
- 2008University of PennsylvaniaResearch associate
Education
Sources and credits
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- Learn on Source, Refine on Target: A Model Transfer Learning Framework with Random Forests
- On the Algorithmic Implementation of Multiclass Kernel-based Vector Machines
- Online Passive-Aggressive Algorithms
- Analysis of Representations for Domain Adaptation
- ACL-08: HLT - Tutorials
- Exact Convex Confidence-Weighted Learning
- Gaussian Margin Machines
- Adaptive Regularization of Weight Vectors
- More Is Better: Large Scale Partially-supervised Sentiment Classification - Appendix
- Weighted Training for Cross-Task Learning
- Crammer, Koby, Technion - Israel Institute of Technology | TOPSCINET



