I am a faculty member in the Hebrew University. My fields of interest are Computational Linguistics and Natural Language Processing. Specifically, I conduct research on semantic (meaning) representation from a computational perspective. My research is tightly linked to statistical learning, language technology, such as machine translation and information extraction, and to the computational modeling of child language acquisition.

Some of the projects/research questions I am engaged in:

• Grammatical and semantic representation, asking what semantic grammatically-relevant information should be manually encoded and how. The representation approach we developed is Universal Conceptual Cognitive Annotation (UCCA), and it is inspired by typological and cognitive approaches to grammar.
• How can we map text (strings) into structured meaning representation? This line of work is deeply tied to machine learning.
• Computational modeling of child language acquisition: how do infants acquire their first words, while making their first steps in acquiring syntax?
• Inducing lexical relations from text: how can distributional information, extracted from statistical regularities in large bodies of text, be used to infer the meanings of words and expressions?
• Unsupervised approaches to grammar: what about grammar can be learned without any manual annotation?

Brief Bio: I am an associate professor at the Hebrew University, working in the departments of Computer Science and Cognitive Science. Previously I was a research associate (post-doc) with Mark Steedman under the GramPlus project. I earned my PhD from the Hebrew University, where my supervisor was Ari Rappoport. During my PhD studies, I was a member of the Azrieli Fellows Program. Before that, I studied mathematics and cognitive sciences in the Hebrew University (BSc, summa cum laude).

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Publications

• Human Learning by Model Feedback: The Dynamics of Iterative Prompting with Midjourney
  Shachar Don-Yehiya, Leshem Choshen and Omri Abend. EMNLP 2023.
  
  
• Event-Location Tracking in Narratives: A Case Study on Holocaust Testimonies
  Eitan Wagner, Renana Keydar and Omri Abend. EMNLP 2023.
  
  
• Improving Cross-lingual Transfer through Subtree-aware Word Reordering
  Ofir Arviv, Dmitry Nikolaev, Taelin Karidi and Omri Abend. Findings of EMNLP 2023.
  
  
• MuLER: Detailed and Scalable Reference-based Evaluation
  Taelin Karidi, Leshem Choshen, Gal Patel and Omri Abend. CoNLL 2023.
  
  
• DisentQA: Disentangling Parametric and Contextual Knowledge with Counterfactual Question Answering
  Ella Neeman, Roee Aharoni, Or Honovich, Leshem Choshen, Idan Szpektor and Omri Abend. ACL 2023. Area Chair Award for Best Paper in the Track.
  
  
• Parallel Context Windows for Large Language Models
  Nir Ratner, Yoav Levine, Yonatan Belinkov, Ori Ram, Inbal Magar, Omri Abend, Ehud Karpas, Amnon Shashua, Kevin Leyton-Brown and Yoav Shoham. ACL 2023.
  [Arxiv]
  
  
• A Large-Scale Multilingual Study of Visual Constraints on Linguistic Selection of Descriptions
  Uri Berger, Lea Frermann, Gabriel Stanovsky and Omri Abend. Findings of EACL 2023.
  [Paper]
  
  
• Evaluating and Improving the Coreference Capabilities of Machine Translation Models
  Asaf Yehudai, Arie Cattan, Omri Abend and Gabriel Stanovsky. EACL 2023.
  [Paper]
  
  
• Topical Segmentation of Spoken Narratives: A Test Case on Holocaust Survivor Testimonies
  Eitan Wagner, Renana Keydar, Amit Pinchevski and Omri Abend. EMNLP 2022.
  
  
• PreQuEL: Quality Estimation of Machine Translation Outputs in Advance
  Shachar Don-Yehiya, Leshem Choshen and Omri Abend. EMNLP 2022.
  
  
• Enhancing the Transformer Decoder with Transition-based Syntax
  Leshem Choshen and Omri Abend. CoNLL 2022.
  
  
• On Neurons Invariant to Sentence Structural Changes in Neural Machine Translation
  Gal Patel, Leshem Choshen and Omri Abend. CoNLL 2022.
  
  
• Cognitive Simplification Operations Improve Text Simplification
  Eytan Chamovitz and Omri Abend. CoNLL 2022.
  [Paper/supp. material]
  
  
• Reinforcement Learning with Large Action Spaces for Neural Machine Translation
  Asaf Yehudai, Leshem Choshen, Lior Fox and Omri Abend. COLING 2022.
  
  
• Semantics-aware Attention Improves Neural Machine Translation
  Aviv Slobodkin, Leshem Choshen and Omri Abend. *SEM 2022.
  
  
• A Computational Acquisition Model for Multimodal Word Categorization
  Uri Berger, Gabriel Stanovsky, Omri Abend, Lea Frermann. NAACL 2022.
  
  
• The Grammar-Learning Trajectories of Neural Language Models
  Leshem Choshen, Guy Hacohen, Daphna Weinshall, Omri Abend. ACL 2022.
  [Paper+appendices: pdf]
  
  
• On the Relation between Syntactic Divergence and Zero-Shot Performance
  Ofir Arviv, Dmitry Nikolaev, Taelin Karidi and Omri Abend. EMNLP 2021.
  [Paper+appendices: pdf][Code/data: github and github]
  
  
• Putting Words in BERT's Mouth: Navigating Contextualized Vector Spaces with Pseudowords
  Taelin Karidi, Yichu Zhou, Nathan Schneider, Omri Abend and Vivek Srikumar. EMNLP 2021.
  [Paper+appendices: pdf][Code/data: github]
  
  
• Q²: Evaluating Factual Consistency in Knowledge-Grounded Dialogues via Question Generation and Question Answering
  Or Honovich, Leshem Choshen, Roee Aharoni, Ella Neeman, Idan Szpektor and Omri Abend. EMNLP 2021.
  [Paper+appendices: pdf][Code/data: github]
  
  
• Paths to Relation Extraction through Semantic Structures
  Jonathan Yellin and Omri Abend. Findings of ACL 2021.
  [Paper+appendices: pdf][Code: github]
  
  
• Mediators in Determining what Processing BERT Performs First
  Aviv Slobodkin, Leshem Choshen and Omri Abend. NAACL 2021.
  [arXiv:pdf]
  
  
• PMI-Masking: Principled Masking of Correlated Spans
  Yoav Levine, Barak Lenz, Opher Lieber, Omri Abend, Kevin Leyton-Brown, Moshe Tennenholtz, Yoav Shoham. ICLR 2021.
  [openreview:pdf]
  
  
• Classifying Syntactic Errors in Learner Language
  Leshem Choshen, Dmitry Nikolaev, Yevgeni Berzak and Omri Abend. and Omri Abend. CoNLL 2020.
  [Paper/supp. material]
  
  
• MRP 2020: The Second Shared Task on Cross Framework and Cross Linguistic Meaning Representation Parsing.
  Stephan Oepen, Omri Abend, Lasha Abzianidze, Johan Bos, Jan Hajic, Daniel Hershcovich, Bin Li, Tim O'Gorman, Nianwen Xue, and Daniel Zeman. CoNLL 2020.
  [Paper/supp. material] [Website]
  
  
• Semantic Structural Decomposition for Neural Machine Translation
  Elior Sulem, Omri Abend and Ari Rappoport. *SEM 2020.
  [Paper/supp. material]
  
  
• Comparison by Conversion: Reverse-Engineering UCCA from Syntax and Lexical Semantics
  Daniel Hershcovich, Nathan Schneider, Dotan Dvir, Jakob Prange, Miryam de Lhoneux and Omri Abend. COLING 2020.
  [Paper/supp. material]
  
  
• Morphosyntactic Predictability of Translationese
  Dmitry Nikolaev, Taelin Karidi, Neta Kenneth, Veronika Mitnik, Lilja Maria Saeboe and Omri Abend. Linguistics Vanguard.
  [Paper: pdf]
  
  
• Fine-Grained Analysis of Cross-Linguistic Syntactic Divergences
  Dmitry Nikolaev, Ofir Arviv, Taelin Karidi, Neta Kenneth, Veronika Mitnik, Lilja Maria Saeboe and Omri Abend. ACL 2020.
  [Paper: Anthology] [arXiv preprint:pdf][Data and Code: github] [Supp. Material: zip]
  
  
• Machine Reading of Historical Events
  Or Honovich, Lucas Torroba Hennigen Omri Abend and Shay B. Cohen. ACL 2020.
  [Paper: Anthology]
  
  
• Language (Re)modelling: Towards Embodied Language Understanding
  Ronen Tamari, Chen Shani, Tom Hope, Miriam R L Petruck, Omri Abend and Dafna Shahaf. ACL 2020.
  [Paper: Anthology][arXiv preprint: pdf]
  
  
• On the Weaknesses of Reinforcement Learning for Neural Machine Translation
  Leshem Choshen, Lior Fox, Zohar Aizenbud and Omri Abend. ICLR 2020.
  [Paper:OpenReview]
  
  
• MRP 2019: Cross-Framework Meaning Representation Parsing
  Stephan Oepen, Omri Abend, Jan Hajic, Daniel Hershcovich, Marco Kuhlmann, Tim O'Gorman and Nianwen Xue. CoNLL 2019.
  [Paper/supp. material] [Website]
  
  
• Automatically Extracting Challenge Sets for Non-local Phenomena in Neural Machine Translation
  Leshem Choshen and Omri Abend. CoNLL 2019.
  [Paper: pdf] [Supp. Material: pdf] [Data: github]
  
  
• Made for Each Other: Broad-coverage Semantic Structures Meet Preposition Supersenses
  Jakob Prange, Nathan Schneider and Omri Abend. CoNLL 2019.
  [Paper: pdf] [Supp. Material: pdf] [Data: github] [Code: see paper]
  
  
• Investigating the Effect of Automatic MWE Recognition on CCG Parsing
  Miryam de Lhoneux, Omri Abend and Mark Steedman.
  In Yannick Parmentier & Jakub Waszczuk (eds.). Representation and Parsing of Multiword Expressions: Current trends, 183-215. Berlin: Language Science Press.
  [Paper: pdf] [Book: html]
  
  
• The Language of Legal and Illegal Activity on the Darknet
  Leshem Choshen^*, Dan Eldad^*, Daniel Hershcovich^*, Elior Sulem^* and Omri Abend. ACL 2019 (long paper).
  [Paper: pdf] [Data: upon request] [Code: github]
  
  
• Semantically Constrained Multilayer Annotation: The Case of Coreference
  Jakob Prange, Nathan Schneider and Omri Abend. DMR Workshop at ACL 2019.
  [Paper: pdf] [Data: github]
  
  
• Preparing SNACS for Subjects and Objects
  Adi Shalev, Jena D. Hwang, Nathan Schneider, Vivek Srikumar, Omri Abend and Ari Rappoport. DMR Workshop at ACL 2019.
  [Paper: pdf]
  
  
• SemEval 2019 Task 1: Cross-lingual Semantic Parsing with UCCA
  Daniel Hershcovich, Zohar Aizenbud, Leshem Choshen, Elior Sulem, Ari Rappoport and Omri Abend. SemEval 2019.
  [Paper: pdf] [Website: codalab]
  
  
• Content Differences in Syntactic and Semantic Representation
  Daniel Hershcovich, Omri Abend and Ari Rappoport. NAACL 2019 (long paper).
  [Paper: pdf] [Supp. Material: pdf] [Data: github] [Code: github]
  
  
• BLEU is Not Suitable for the Evaluation of Text Simplification
  Elior Sulem, Omri Abend and Ari Rappoport. EMNLP 2018 (short paper).
  [Paper: pdf] [Code: github]
  
  
• Universal Dependency Parsing with a General Transition-Based DAG Parser
  Daniel Hershcovich, Omri Abend and Ari Rappoport. CoNLL 2018 Shared Task on Multilingual Universal Dependencies Parsing.
  [Paper: pdf]
  
  
• Automatic Metric Validation for Grammatical Error Correction.
  Leshem Choshen and Omri Abend. ACL 2018 (long paper).
  [Paper: pdf] [Code: github]
  
  
• Inherent Biases in Reference-based Evaluation for Grammatical Error Correction and Text Simplification.
  Leshem Choshen and Omri Abend. ACL 2018 (long paper).
  [Paper: pdf] [Supp. Material: pdf] [Code: github]
  
  
• Multitask Parsing Across Semantic Representations.
  Daniel Hershcovich, Omri Abend and Ari Rappoport. ACL 2018 (long paper).
  [Paper: pdf] [Supp. Material: pdf] [Code: github]
  
  
• Simple and Effective Text Simplification using Semantic and Neural Methods.
  Elior Sulem, Omri Abend and Ari Rappoport. ACL 2018 (long paper).
  [Paper: pdf] [Data: github]
  
  
• Comprehensive Supersense Disambiguation of English Prepositions and Possessives.
  Nathan Schneider, Jena D. Hwang, Vivek Srikumar, Jakob Prange, Austin Blodgett, Sarah R. Moeller, Aviram Stern, Adi Bitan and Omri Abend. ACL 2018 (long paper).
  [Paper: pdf] [Supp. Material: pdf] [Code: github]
  
  
• Reference-less Measure of Faithfulness for Grammatical Error Correction.
  Leshem Choshen and Omri Abend. NAACL 2018 (short paper).
  [Paper: pdf] [Supp. Material: pdf] [Code: github]
  
  
• Semantic Structural Evaluation for Text Simplification.
  Elior Sulem, Omri Abend and Ari Rappoport. NAACL 2018 (long paper).
  [Paper: pdf] [Data & Code: github]
  
  
• Bootstrapping Language Acquisition.
  Omri Abend, Tom Kwiatkowski, Nathaniel J. Smith, Sharon Goldwater and Mark Steedman. Cognition, Vol. 164, pp. 116-143, 2017.
  [Pre-print: pdf] [Journal Copy: link] [Data: tgz]
  
  
• The State of the Art in Semantic Representation.
  Omri Abend and Ari Rappoport. ACL 2017 (long paper).
  [Paper: pdf]
  
  
• A Transition-Based Directed Acyclic Graph Parser for UCCA.
  Daniel Hershcovich, Omri Abend and Ari Rappoport. ACL 2017 (long paper). Outstanding Paper Award.
  [Paper: pdf] [Supp. Material: pdf] [Code & Data: github] [Demo]
  
  
• UCCAApp: Web-application for Syntactic and Semantic Phrase-based Annotation.
  Omri Abend, Shai Yerushalmi and Ari Rappoport. ACL 2017 (demo paper).
  [Paper: pdf] [Code: github] [Demo]
  
  
• HUME: Human UCCA-Based Evaluation of Machine Translation.
  Alexandra Birch^*, Omri Abend^*, Ondřej Bojar^* and Barry Haddow^*, EMNLP 2016 (long paper).
  * Equal contribution.
  [Paper: pdf] [Data: github] [Demo]
  
  
• Lexical Event Ordering with an Edge-Factored Model.
  Omri Abend, Shay B. Cohen and Mark Steedman, NAACL 2015 (long paper).
  [Paper: pdf] [Data: download]
  
  
• Conceptual Annotations Preserve Structure Across Translations: A French-English Case Study.
  Elior Sulem, Omri Abend and Ari Rappoport,
  ACL 2015 Workshop on Semantics-Driven Statistical Machine Translation (S2MT).
  [Paper: pdf]
  
  
• Lexical Inference over Multi-Word Predicates: A Distributional Approach.
  Omri Abend, Shay B. Cohen and Mark Steedman, ACL 2014 (long paper).
  [Paper: pdf] [Source Code: download]
  
  
• Universal Conceptual Cognitive Annotation (UCCA).
  Omri Abend and Ari Rappoport, ACL 2013 (long paper).
  [Paper: pdf][Data and Web-app: link]
  
  
• UCCA: A Semantics-based Grammatical Annotation Scheme.
  Omri Abend and Ari Rappoport, IWCS 2013 (long paper).
  [Paper: pdf]
  
  
• Learnability-based Syntactic Annotation Design.
  Roy Schwartz, Omri Abend and Ari Rappoport, COLING 2012 (long paper).
  [Paper: pdf] [Source Code: download]
  
  
• Neutralizing Linguistically Problematic Annotations in Unsupervised Dependency Parsing Evaluation.
  Roy Schwartz, Omri Abend, Roi Reichart and Ari Rappoport, ACL 2011 (long paper).
  [Paper: pdf] [Source Code: download]
  
  
• Improved Unsupervised POS Induction through Prototype Discovery.
  Omri Abend, Roi Reichart and Ari Rappoport, ACL 2010 (long paper).
  [Paper: pdf] [Source Code: download]
  
  
• Fully Unsupervised Core-Adjunct Argument Classification.
  Omri Abend and Ari Rappoport ACL 2010 (long paper).
  [Paper: pdf]
  
  
• Type Level Clustering Evaluation: New Measures and a POS Induction Case Study.
  Roi Reichart^*, Omri Abend^* and Ari Rappoport, CoNLL 2010 (long paper).
  * Equal contribution.
  [Paper: pdf]
  
  
• Unsupervised Argument Identification for Semantic Role Labeling.
  Omri Abend, Roi Reichart and Ari Rappoport, ACL 2009 (long paper).
  [Paper: pdf]
  
  
• A Supervised Algorithm for Verb Disambiguation into VerbNet Classes.
  Omri Abend, Roi Reichart and Ari Rappoport, COLING 2008 (long paper).
  [Paper: pdf] [Data: upon request]
  
  

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