Shai Ben-David

Professor

David R. Cheriton School of Computer Science
University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada
, N2L 3G1
Email: shai@cs.uwaterloo.ca
Phone: +1 519 888 4567 ext. 37523
Fax: +1 519 885-1208

Home

Academic Biography
Shai Ben-David grew up in
Jerusalem, Israel. He attended the Hebrew University studying physics, mathematics and psychology. He received his PhD under the supervision of Saharon Shelah and Menachem Magidor for a thesis in set theory (on non-provability of infinite combinatorial statements).
Dr. Ben-David was a postdoctoral fellow at the University of Toronto in the Mathematics and the Computer Science departments, and in 1987 joined the faculty of the CS Department at the Technion (Israel Institute Technology). He held visiting faculty positions at the Australian National University in Canberra (1997-8) and at Cornell University (2001-2004). In August 2004 he joined the School of Computer Science at the University of Waterloo.

Research Interests

My research interests span a wide spectrum of topics in the foundations of computer science and its applications, with a particular emphasis on statistical and computational machine learning. The common thread throughout my research is the interplay between mathematical theories and real world problems.

In recent years much of my research has been directed towards providing mathematical analysis for popular machine learning and data mining paradigms that seem to lack clear theoretical justification. I have looked into the performance guarantees one can provide for Support Vector Machines (with pessimistic conclusions), at Semi-Supervised Learning (once again, coming up with some inherent limitations of that approach), at the Learning-To-Learn paradigm (providing some theoretical justifications to common practices), at the Stability method for determining the number of clusters in a data set (see my COLT06, COLT07 papers on that and a recent submission), and quite a few more topics.

  Clustering is a really large area that also suffers from the lack of mathematical foundations, and I have been working extensively trying to address the theoretical challenges  of developing such a theory (see my recent submissions with Ackerman as well as my ’05 paper with von Luxburg)
For more details see the links to my papers, talks, and professional activities.

2009 Publications

            Learning Low-Density Separators

S. Ben-David, Tyler Lu, David Pal, and Miroslava Stakova.  Proceedings of the Twelfth International Conference on
Artificial Intelligence and Statistics, 2009.

           Which Data Sets are Clusterable? - A Theoretical Study of Clusterability
Margarita Ackerman and S. Ben-David. Proceedings of the Twelfth International Conference on
Artificial Intelligence and Statistics, 2009.

          A Uniqueness Theorem for Clustering.

Reza Bosagh Zadeh, Shai Ben-David. Proceedings of UAI 2009.

 

            Agnostic Online Learning.

Shai Ben-David, David Pal and Shai Shalev-Shwartz. Proceedings of COLT 2009.

 

           Modeling and Querying Possible Repairs in Duplicate Detection
George Beskales, Mohamed A. Soliman, Ihab F. Ilyas and Shai Ben-David
To Appear in Proceedings of VLDB 2009.

 

2008 Publications

 

            Measures of Clustering Quality: A Working Set of Axioms for Clustering
            Margareta Ackerman and Shai Ben-David, Proceedings of Neural Information Processing Systems (NIPS 2008)

 

            Does Unlabeled Data Provably Help? Worst-case Analysis of the Sample Complexity of Semi-Supervised Learning

            S.Ben-David, Tyler Lu and David Pal.  To appear in COLT 2008

 

            Relating clustering stability to properties of cluster boundaries

            S. Ben-David and Ulrike von Luxburg. To appear in COLT 2008

 

           

            A Notion of Task relatedness Yiealding Provable Multiple-task Learning Guarantees
             S. Ben-David and Reba Schuller-Borbely. (Machine Learning Journal, 2008).

 

            A framework for addressing the Training/Test Distributions Gap

            S. Ben-David. Book chapter. To appear in ``Data Shift in Machine Learning'' MIT press.



2006-7 Publications

 

            A Framework for Statistical Clustering with Constant Time Approximation for K-Means Clustering

            S. Ben-David. (Machine Learning Journal, 2007)

 

            Stability of K-Means

            S. Ben-David, D. Pal, H. ulrich Simon(Proceedings of COLT07)

 

            Analysis of Representations for Domain Adaptation

            S. Ben-David, J. Blitzer, K. Crammer, F. Pereira (Proceedings of NIPS'06)

 

            Learning Bounds for Support Vector Machines with Learned Kernels

            Nathan Srebro, Shai Ben-David (Proceedings of COLT'06)

 

            A Sober Look at Stability of Clustering

            S. Ben-David, U. von Luxburg, D. Pal Winner of Best Student Paper Award in COLT'06

 

            Alternative Measures of Computational Complexity

            S. Ben-David TAMC'06


Towards a Statistical Theory of Clustering
(with Ulrike von Luxburg) - PASCAL Workshop on Statistics and Optimization of Clustering (2005)

Non-Parametric Change Detection in 2D Random Sensor Fields
(with Ting He and Lang Tong) Winner of Best Student Paper Award in ICASSP 2005

Publications

Talks

Professional activities

Teaching