Ido Dagan עידו דגן
Department of Computer Science, Bar Ilan University

[Contact | Short Bio | Activities | Teaching | Students |Publications]

Ido Dagan

Contact Information

Natural Language Processing Lab
Department of Computer Science
Bar Ilan University,
Ramat Gan, 52900, Israel


Phone: +972-3-5317620
Mobile:  +972-54-4395336
Fax: +972-3-7384056


My research interests for over a decade have been within empirical and learning methods for language processing, often operating over rich linguistic representations, with particular emphasis on unsupervised semantic learning. In the last few years we have introduced textual entailment as a generic framework for applied semantic inference over texts. With our colleagues, we organized the three rounds of the PASCAL Recognizing Textual Entailment (RTE) Challenges (2004-2007), which attracted dozens of research groups and became the primary forum for empirical evaluation of semantic inference systems. At the Bar Ilan NLP group we develop computational models of textual entailment, including automatic knowledge acquisition, semantic inference, and information extraction and retrieval applications.

Some useful links for textual entailment:


Short Bio

Ido Dagan holds B.Sc. (Summa Cum Laude) and Ph.D. degrees in Computer Science from the Technion, Israel. He conducted his Ph.D. research in collaboration with the IBM Haifa Scientific Center, where he was a research fellow in 1991. During 1992-1994 he was a Member of Technical Staff at AT&T Bell Laboratories. During 1994-1998 he has been at the Department of Computer Science of Bar Ilan University, to which he returned in 2003. During 1998-2003 he was co-founder and CTO of a text categorization startup company, FocusEngine, and VP of Technology at LingoMotors, a Cambridge Massachusetts company which acquired FocusEngine.


Public Organizational Activities

  • Journal Editorial Boards
    • Computational Linguistics (1995–1997)
    • Machine Translation
    • Natural Language Engineering


  • Program Chairing and Organization
    • Program co-chair of the Fourth ACL SIGDAT International Workshop on Very Large Corpora (WVLC), 1996
    • Organizing the Israeli Seminar on Computational Linguistics (ISCOL), 2004 & 2007
    • Program co-chair of the Ninth Conference on Computational Natural Language Learning (CONLL), 2005
    • Initiator, co-organizer and program co-chair of the 1st, 2nd and 3rd PASCAL Recognizing Textual Entailment Challenges and Workshops, 2004-2007 (Joint ACL workshop at 2007)
    • Program co-chair and co-organizer of the ACL Workshop on Empirical Modeling of Semantic Equivalence and Entailment, 2005


  • Boards and Committees
    • Advisory Board of the European Chapter of the Association for Computational Linguistics (EACL), 2003-2006
    • Board of SIGNLL - the Association for Computational Linguistics Special Interest Group for Natural Language Learning
    • Board of SIGDAT – the Association for Computational Linguistics Special Interest Group for Linguistic Data and Corpus-Based Approaches to NLP
    • Chairman of the steering committee of the Knowledge Center for Processing Hebrew


  • Summer school teaching at ESSLLI 1993 and 1998, and at ELSNET 1994, 1995 and 2000


  • Conference tutorials at ACL 1996, 1998 and 2007, COLING 1996, and RANLP 2003





MS.c. Thesis

  • Shlomit Hazan (with Dr. Ronen Feldman): Discovery and clustering of association rules in large data bases. 1997.
  • Erez Lotan: Automatic construction of a statistical thesaurus. 1998.
  • Alex Avramovitch: An Internet Crawler for automatic corpus and thesaurus construction. 1998.
  • Shelly Katz (with Dr. Ariel Frank): Intelligent information filtering within information harvesting in the Internet. 1998.
  • Roman Mitnitsky: A personal search agent for Internet users. 1998.
  • Michal Finkelstein-Landau: Term-based summarization and knowledge discovery in texts. 1999.
  • Marina Risher: Automatic query generation. 2001.
  • Ehud Conley: Seq_align: A parsing-independent bilingual sequence alignment algorithm. 2002.
  • Idan Szpektor (with Prof. Yossi Matias). Scaling Web Based Acquisition of Entailment Relations. 2005.
  • Shachar Mirkin (with Dr. Ari Rappoport). Integrating patterns and distribution similarity info for lexical entailment acquisition. 2006.
  • Tal Itzhak Ron. Lexical Acquisition of Nominalization Entailment Rules Using Online Lexical Resources. 2006.
  • Efrat Hershkovitz. Implicit word sense disambiguation via context-sensitive lexical entailment. 2006.
  • Moshe Friedman (with Prof. Moshe Koppel). A Machine Learning Approach for Coreference Resolution in Probabilistic Textual Entailment. 2007.
  • Libby Berkovitch. Unsupervised text categorization. 2008.
  • Eyal Shnarch. Lexical Entailment and its Extraction from Wikipedia. 2008.
  • Ephi Sachs. Semantic expansion for information retrieval. 2008.
  • Lili Kotlerman. Distributional learning of textual entailment relations.
  • Roni Ben Aharon. Generation of Textual Entailment Rules From FrameNet. 2010.
  • Hila Weisman. Learning Verb Inference Rules from Linguistically-Motivated Evidence. 2013.
  • Naomi Zeichner. Evaluating and Improving Inference-Rules via CrowdSourcing. 2013.
  • Amnon Lotan. A Syntax-based Rule-base for Textual Entailment and a Semantic Truth Value Annotator. 2013.
  • Ofer Bronstein.

Ph.D. Thesis

  • Zvika Marx (with Prof. Eli Shamir). Structure Based Computational Aspects of Similarity and Analogy in Natural Language. 2005.
  • Yuval Krymolowski (with Prof. Amihood Amir). Partial Parsing using Memory-Based Sequence Learning. 2006.
  • Oren Glickman (with Prof. Moshe Koppel). Generic Shallow Semantic Inference based on Automatic Knowledge Acquisition. 2006.
  • Maayan Gefet (with Dr. Dror Feitelson). Automatic construction of ontology from text. 2006.
  • Roy Bar Haim. Probabilistic Lexical-Syntactic Inference for Textual Entailment. 2009.
  • Idan Szpektor. Automatic Acquisition of Lexical-Syntactic Entailment Rules. 2009.
  • Shachar Mirkin. Utilization of textual entailment in NLP applications. 2012.
  • Jonathan Berant. Ontology Learning and Population in domain specific corpora. 2012.
  • Eyal Shnarch. Automatic Lexical Knowledge Acquisition and its usage within NLP applications. 2013.
  • Omer Levy.
  • Oren Melamud.
  • Lili Kotlerman.
  • Chaya Liebeskind.
  • Asher Stern.