Dima Taji


Camel Treebank: An Open Multi-genre Arabic Dependency Treebank
Nizar Habash | Muhammed AbuOdeh | Dima Taji | Reem Faraj | Jamila El Gizuli | Omar Kallas
Proceedings of the Thirteenth Language Resources and Evaluation Conference

We present the Camel Treebank (CAMELTB), a 188K word open-source dependency treebank of Modern Standard and Classical Arabic. CAMELTB 1.0 includes 13 sub-corpora comprising selections of texts from pre-Islamic poetry to social media online commentaries, and covering a range of genres from religious and philosophical texts to news, novels, and student essays. The texts are all publicly available (out of copyright, creative commons, or under open licenses). The texts were morphologically tokenized and syntactically parsed automatically, and then manually corrected by a team of trained annotators. The annotations follow the guidelines of the Columbia Arabic Treebank (CATiB) dependency representation. We discuss our annotation process and guideline extensions, and we present some initial observations on lexical and syntactic differences among the annotated sub-corpora. This corpus will be publicly available to support and encourage research on Arabic NLP in general and on new, previously unexplored genres that are of interest to a wider spectrum of researchers, from historical linguistics and digital humanities to computer-assisted language pedagogy.


PALMYRA 2.0: A Configurable Multilingual Platform Independent Tool for Morphology and Syntax Annotation
Dima Taji | Nizar Habash
Proceedings of the Fourth Workshop on Universal Dependencies (UDW 2020)

We present PALMYRA 2.0, a graphical dependency-tree visualization and editing software. PALMYRA 2.0 is designed to be highly configurable to any dependency parsing representation, and to enable the annotation of a multitude of linguistic features. It uses an intuitive interface that relies on drag-and-drop utilities as well as pop-up menus and keyboard shortcuts that can be easily specified.

Multitask Easy-First Dependency Parsing: Exploiting Complementarities of Different Dependency Representations
Yash Kankanampati | Joseph Le Roux | Nadi Tomeh | Dima Taji | Nizar Habash
Proceedings of the 28th International Conference on Computational Linguistics

In this paper we present a parsing model for projective dependency trees which takes advantage of the existence of complementary dependency annotations which is the case in Arabic, with the availability of CATiB and UD treebanks. Our system performs syntactic parsing according to both annotation types jointly as a sequence of arc-creating operations, and partially created trees for one annotation are also available to the other as features for the score function. This method gives error reduction of 9.9% on CATiB and 6.1% on UD compared to a strong baseline, and ablation tests show that the main contribution of this reduction is given by sharing tree representation between tasks, and not simply sharing BiLSTM layers as is often performed in NLP multitask systems.

CAMeL Tools: An Open Source Python Toolkit for Arabic Natural Language Processing
Ossama Obeid | Nasser Zalmout | Salam Khalifa | Dima Taji | Mai Oudah | Bashar Alhafni | Go Inoue | Fadhl Eryani | Alexander Erdmann | Nizar Habash
Proceedings of the Twelfth Language Resources and Evaluation Conference

We present CAMeL Tools, a collection of open-source tools for Arabic natural language processing in Python. CAMeL Tools currently provides utilities for pre-processing, morphological modeling, Dialect Identification, Named Entity Recognition and Sentiment Analysis. In this paper, we describe the design of CAMeL Tools and the functionalities it provides.


Palmyra: A Platform Independent Dependency Annotation Tool for Morphologically Rich Languages
Talha Javed | Nizar Habash | Dima Taji
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

CoNLL-UL: Universal Morphological Lattices for Universal Dependency Parsing
Amir More | Özlem Çetinoğlu | Çağrı Çöltekin | Nizar Habash | Benoît Sagot | Djamé Seddah | Dima Taji | Reut Tsarfaty
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

An Arabic Morphological Analyzer and Generator with Copious Features
Dima Taji | Salam Khalifa | Ossama Obeid | Fadhl Eryani | Nizar Habash
Proceedings of the Fifteenth Workshop on Computational Research in Phonetics, Phonology, and Morphology

We introduce CALIMA-Star, a very rich Arabic morphological analyzer and generator that provides functional and form-based morphological features as well as built-in tokenization, phonological representation, lexical rationality and much more. This tool includes a fast engine that can be easily integrated into other systems, as well as an easy-to-use API and a web interface. CALIMA-Star also supports morphological reinflection. We evaluate CALIMA-Star against four commonly used analyzers for Arabic in terms of speed and morphological content.


Low Resourced Machine Translation via Morpho-syntactic Modeling: The Case of Dialectal Arabic
Alexander Erdmann | Nizar Habash | Dima Taji | Houda Bouamor
Proceedings of Machine Translation Summit XVI: Research Track

Universal Dependencies for Arabic
Dima Taji | Nizar Habash | Daniel Zeman
Proceedings of the Third Arabic Natural Language Processing Workshop

We describe the process of creating NUDAR, a Universal Dependency treebank for Arabic. We present the conversion from the Penn Arabic Treebank to the Universal Dependency syntactic representation through an intermediate dependency representation. We discuss the challenges faced in the conversion of the trees, the decisions we made to solve them, and the validation of our conversion. We also present initial parsing results on NUDAR.

A Parallel Corpus for Evaluating Machine Translation between Arabic and European Languages
Nizar Habash | Nasser Zalmout | Dima Taji | Hieu Hoang | Maverick Alzate
Proceedings of the 15th Conference of the European Chapter of the Association for Computational Linguistics: Volume 2, Short Papers

We present Arab-Acquis, a large publicly available dataset for evaluating machine translation between 22 European languages and Arabic. Arab-Acquis consists of over 12,000 sentences from the JRC-Acquis (Acquis Communautaire) corpus translated twice by professional translators, once from English and once from French, and totaling over 600,000 words. The corpus follows previous data splits in the literature for tuning, development, and testing. We describe the corpus and how it was created. We also present the first benchmarking results on translating to and from Arabic for 22 European languages.

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CoNLL 2017 Shared Task: Multilingual Parsing from Raw Text to Universal Dependencies
Daniel Zeman | Martin Popel | Milan Straka | Jan Hajič | Joakim Nivre | Filip Ginter | Juhani Luotolahti | Sampo Pyysalo | Slav Petrov | Martin Potthast | Francis Tyers | Elena Badmaeva | Memduh Gokirmak | Anna Nedoluzhko | Silvie Cinková | Jan Hajič jr. | Jaroslava Hlaváčová | Václava Kettnerová | Zdeňka Urešová | Jenna Kanerva | Stina Ojala | Anna Missilä | Christopher D. Manning | Sebastian Schuster | Siva Reddy | Dima Taji | Nizar Habash | Herman Leung | Marie-Catherine de Marneffe | Manuela Sanguinetti | Maria Simi | Hiroshi Kanayama | Valeria de Paiva | Kira Droganova | Héctor Martínez Alonso | Çağrı Çöltekin | Umut Sulubacak | Hans Uszkoreit | Vivien Macketanz | Aljoscha Burchardt | Kim Harris | Katrin Marheinecke | Georg Rehm | Tolga Kayadelen | Mohammed Attia | Ali Elkahky | Zhuoran Yu | Emily Pitler | Saran Lertpradit | Michael Mandl | Jesse Kirchner | Hector Fernandez Alcalde | Jana Strnadová | Esha Banerjee | Ruli Manurung | Antonio Stella | Atsuko Shimada | Sookyoung Kwak | Gustavo Mendonça | Tatiana Lando | Rattima Nitisaroj | Josie Li
Proceedings of the CoNLL 2017 Shared Task: Multilingual Parsing from Raw Text to Universal Dependencies

The Conference on Computational Natural Language Learning (CoNLL) features a shared task, in which participants train and test their learning systems on the same data sets. In 2017, the task was devoted to learning dependency parsers for a large number of languages, in a real-world setting without any gold-standard annotation on input. All test sets followed a unified annotation scheme, namely that of Universal Dependencies. In this paper, we define the task and evaluation methodology, describe how the data sets were prepared, report and analyze the main results, and provide a brief categorization of the different approaches of the participating systems.


The Columbia University - New York University Abu Dhabi SIGMORPHON 2016 Morphological Reinflection Shared Task Submission
Dima Taji | Ramy Eskander | Nizar Habash | Owen Rambow
Proceedings of the 14th SIGMORPHON Workshop on Computational Research in Phonetics, Phonology, and Morphology

CamelParser: A system for Arabic Syntactic Analysis and Morphological Disambiguation
Anas Shahrour | Salam Khalifa | Dima Taji | Nizar Habash
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: System Demonstrations

In this paper, we present CamelParser, a state-of-the-art system for Arabic syntactic dependency analysis aligned with contextually disambiguated morphological features. CamelParser uses a state-of-the-art morphological disambiguator and improves its results using syntactically driven features. The system offers a number of output formats that include basic dependency with morphological features, two tree visualization modes, and traditional Arabic grammatical analysis.