Nizar Habash


2021

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SIGMORPHON 2021 Shared Task on Morphological Reinflection: Generalization Across Languages
Tiago Pimentel | Maria Ryskina | Sabrina J. Mielke | Shijie Wu | Eleanor Chodroff | Brian Leonard | Garrett Nicolai | Yustinus Ghanggo Ate | Salam Khalifa | Nizar Habash | Charbel El-Khaissi | Omer Goldman | Michael Gasser | William Lane | Matt Coler | Arturo Oncevay | Jaime Rafael Montoya Samame | Gema Celeste Silva Villegas | Adam Ek | Jean-Philippe Bernardy | Andrey Shcherbakov | Aziyana Bayyr-ool | Karina Sheifer | Sofya Ganieva | Matvey Plugaryov | Elena Klyachko | Ali Salehi | Andrew Krizhanovsky | Natalia Krizhanovsky | Clara Vania | Sardana Ivanova | Aelita Salchak | Christopher Straughn | Zoey Liu | Jonathan North Washington | Duygu Ataman | Witold Kieraś | Marcin Woliński | Totok Suhardijanto | Niklas Stoehr | Zahroh Nuriah | Shyam Ratan | Francis M. Tyers | Edoardo M. Ponti | Grant Aiton | Richard J. Hatcher | Emily Prud'hommeaux | Ritesh Kumar | Mans Hulden | Botond Barta | Dorina Lakatos | Gábor Szolnok | Judit Ács | Mohit Raj | David Yarowsky | Ryan Cotterell | Ben Ambridge | Ekaterina Vylomova
Proceedings of the 18th SIGMORPHON Workshop on Computational Research in Phonetics, Phonology, and Morphology

This year's iteration of the SIGMORPHON Shared Task on morphological reinflection focuses on typological diversity and cross-lingual variation of morphosyntactic features. In terms of the task, we enrich UniMorph with new data for 32 languages from 13 language families, with most of them being under-resourced: Kunwinjku, Classical Syriac, Arabic (Modern Standard, Egyptian, Gulf), Hebrew, Amharic, Aymara, Magahi, Braj, Kurdish (Central, Northern, Southern), Polish, Karelian, Livvi, Ludic, Veps, Võro, Evenki, Xibe, Tuvan, Sakha, Turkish, Indonesian, Kodi, Seneca, Asháninka, Yanesha, Chukchi, Itelmen, Eibela. We evaluate six systems on the new data and conduct an extensive error analysis of the systems' predictions. Transformer-based models generally demonstrate superior performance on the majority of languages, achieving >90% accuracy on 65% of them. The languages on which systems yielded low accuracy are mainly under-resourced, with a limited amount of data. Most errors made by the systems are due to allomorphy, honorificity, and form variation. In addition, we observe that systems especially struggle to inflect multiword lemmas. The systems also produce misspelled forms or end up in repetitive loops (e.g., RNN-based models). Finally, we report a large drop in systems' performance on previously unseen lemmas.

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A Cloud-based User-Centered Time-Offset Interaction Application
Alberto Chierici | Tyeece Kiana Fredorcia Hensley | Wahib Kamran | Kertu Koss | Armaan Agrawal | Erin Meekhof | Goffredo Puccetti | Nizar Habash
Proceedings of the 22nd Annual Meeting of the Special Interest Group on Discourse and Dialogue

Time-offset interaction applications (TOIA) allow simulating conversations with people who have previously recorded relevant video utterances, which are played in response to their interacting user. TOIAs have great potential for preserving cross-generational and cross-cultural histories, online teaching, simulated interviews, etc. Current TOIAs exist in niche contexts involving high production costs. Democratizing TOIA presents different challenges when creating appropriate pre-recordings, designing different user stories, and creating simple online interfaces for experimentation. We open-source TOIA 2.0, a user-centered time-offset interaction application, and make it available for everyone who wants to interact with people’s pre-recordings, or create their pre-recordings.

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A View From the Crowd: Evaluation Challenges for Time-Offset Interaction Applications
Alberto Chierici | Nizar Habash
Proceedings of the Workshop on Human Evaluation of NLP Systems (HumEval)

Dialogue systems like chatbots, and tasks like question-answering (QA) have gained traction in recent years; yet evaluating such systems remains difficult. Reasons include the great variety in contexts and use cases for these systems as well as the high cost of human evaluation. In this paper, we focus on a specific type of dialogue systems: Time-Offset Interaction Applications (TOIAs) are intelligent, conversational software that simulates face-to-face conversations between humans and pre-recorded human avatars. Under the constraint that a TOIA is a single output system interacting with users with different expectations, we identify two challenges: first, how do we define a ‘good’ answer? and second, what’s an appropriate metric to use? We explore both challenges through the creation of a novel dataset that identifies multiple good answers to specific TOIA questions through the help of Amazon Mechanical Turk workers. This ‘view from the crowd’ allows us to study the variations of how TOIA interrogators perceive its answers. Our contributions include the annotated dataset that we make publicly available and the proposal of Success Rate @k as an evaluation metric that is more appropriate than the traditional QA’s and information retrieval’s metrics.

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Proceedings of the Sixth Arabic Natural Language Processing Workshop
Nizar Habash | Houda Bouamor | Hazem Hajj | Walid Magdy | Wajdi Zaghouani | Fethi Bougares | Nadi Tomeh | Ibrahim Abu Farha | Samia Touileb
Proceedings of the Sixth Arabic Natural Language Processing Workshop

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The Interplay of Variant, Size, and Task Type in Arabic Pre-trained Language Models
Go Inoue | Bashar Alhafni | Nurpeiis Baimukan | Houda Bouamor | Nizar Habash
Proceedings of the Sixth Arabic Natural Language Processing Workshop

In this paper, we explore the effects of language variants, data sizes, and fine-tuning task types in Arabic pre-trained language models. To do so, we build three pre-trained language models across three variants of Arabic: Modern Standard Arabic (MSA), dialectal Arabic, and classical Arabic, in addition to a fourth language model which is pre-trained on a mix of the three. We also examine the importance of pre-training data size by building additional models that are pre-trained on a scaled-down set of the MSA variant. We compare our different models to each other, as well as to eight publicly available models by fine-tuning them on five NLP tasks spanning 12 datasets. Our results suggest that the variant proximity of pre-training data to fine-tuning data is more important than the pre-training data size. We exploit this insight in defining an optimized system selection model for the studied tasks.

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Automatic Romanization of Arabic Bibliographic Records
Fadhl Eryani | Nizar Habash
Proceedings of the Sixth Arabic Natural Language Processing Workshop

International library standards require cataloguers to tediously input Romanization of their catalogue records for the benefit of library users without specific language expertise. In this paper, we present the first reported results on the task of automatic Romanization of undiacritized Arabic bibliographic entries. This complex task requires the modeling of Arabic phonology, morphology, and even semantics. We collected a 2.5M word corpus of parallel Arabic and Romanized bibliographic entries, and benchmarked a number of models that vary in terms of complexity and resource dependence. Our best system reaches 89.3% exact word Romanization on a blind test set. We make our data and code publicly available.

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NADI 2021: The Second Nuanced Arabic Dialect Identification Shared Task
Muhammad Abdul-Mageed | Chiyu Zhang | AbdelRahim Elmadany | Houda Bouamor | Nizar Habash
Proceedings of the Sixth Arabic Natural Language Processing Workshop

We present the findings and results of theSecond Nuanced Arabic Dialect IdentificationShared Task (NADI 2021). This Shared Taskincludes four subtasks: country-level ModernStandard Arabic (MSA) identification (Subtask1.1), country-level dialect identification (Subtask1.2), province-level MSA identification (Subtask2.1), and province-level sub-dialect identifica-tion (Subtask 2.2). The shared task dataset cov-ers a total of 100 provinces from 21 Arab coun-tries, collected from the Twitter domain. A totalof 53 teams from 23 countries registered to par-ticipate in the tasks, thus reflecting the interestof the community in this area. We received 16submissions for Subtask 1.1 from five teams, 27submissions for Subtask 1.2 from eight teams,12 submissions for Subtask 2.1 from four teams,and 13 Submissions for subtask 2.2 from fourteams.

2020

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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.

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Utilizing Subword Entities in Character-Level Sequence-to-Sequence Lemmatization Models
Nasser Zalmout | Nizar Habash
Proceedings of the 28th International Conference on Computational Linguistics

In this paper we present a character-level sequence-to-sequence lemmatization model, utilizing several subword features in multiple configurations. In addition to generic n-gram embeddings (using FastText), we experiment with concatenative (stems) and templatic (roots and patterns) morphological subwords. We present several architectures that embed these features directly at the encoder side, or learn them jointly at the decoder side with a multitask learning architecture. The results indicate that using the generic n-gram embeddings (through FastText) outperform the other linguistically-driven subwords. We use Modern Standard Arabic and Egyptian Arabic as test cases, with up to 22% and 13% relative error reduction, respectively, from a strong baseline. An error analysis shows that our best system is even able to handle word/lemma pairs that are both unseen in the training data.

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An Online Readability Leveled Arabic Thesaurus
Zhengyang Jiang | Nizar Habash | Muhamed Al Khalil
Proceedings of the 28th International Conference on Computational Linguistics: System Demonstrations

This demo paper introduces the online Readability Leveled Arabic Thesaurus interface. For a given user input word, this interface provides the word’s possible lemmas, roots, English glosses, related Arabic words and phrases, and readability on a five-level readability scale. This interface builds on and connects multiple existing Arabic resources and processing tools. This one-of-a-kind system enables Arabic speakers and learners to benefit from advances in Arabic computational linguistics technologies. Feedback from users of the system will help the developers to identify lexical coverage gaps and errors. A live link to the demo is available at: http://samer.camel-lab.com/.

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The Margarita Dialogue Corpus: A Data Set for Time-Offset Interactions and Unstructured Dialogue Systems
Alberto Chierici | Nizar Habash | Margarita Bicec
Proceedings of the 12th Language Resources and Evaluation Conference

Time-Offset Interaction Applications (TOIAs) are systems that simulate face-to-face conversations between humans and digital human avatars recorded in the past. Developing a well-functioning TOIA involves several research areas: artificial intelligence, human-computer interaction, natural language processing, question answering, and dialogue systems. The first challenges are to define a sensible methodology for data collection and to create useful data sets for training the system to retrieve the best answer to a user’s question. In this paper, we present three main contributions: a methodology for creating the knowledge base for a TOIA, a dialogue corpus, and baselines for single-turn answer retrieval. We develop the methodology using a two-step strategy. First, we let the avatar maker list pairs by intuition, guessing what possible questions a user may ask to the avatar. Second, we record actual dialogues between random individuals and the avatar-maker. We make the Margarita Dialogue Corpus available to the research community. This corpus comprises the knowledge base in text format, the video clips for each answer, and the annotated dialogues.

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A Large-Scale Leveled Readability Lexicon for Standard Arabic
Muhamed Al Khalil | Nizar Habash | Zhengyang Jiang
Proceedings of the 12th Language Resources and Evaluation Conference

We present a large-scale 26,000-lemma leveled readability lexicon for Modern Standard Arabic. The lexicon was manually annotated in triplicate by language professionals from three regions in the Arab world. The annotations show a high degree of agreement; and major differences were limited to regional variations. Comparing lemma readability levels with their frequencies provided good insights in the benefits and pitfalls of frequency-based readability approaches. The lexicon will be publicly available.

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Morphological Analysis and Disambiguation for Gulf Arabic: The Interplay between Resources and Methods
Salam Khalifa | Nasser Zalmout | Nizar Habash
Proceedings of the 12th Language Resources and Evaluation Conference

In this paper we present the first full morphological analysis and disambiguation system for Gulf Arabic. We use an existing state-of-the-art morphological disambiguation system to investigate the effects of different data sizes and different combinations of morphological analyzers for Modern Standard Arabic, Egyptian Arabic, and Gulf Arabic. We find that in very low settings, morphological analyzers help boost the performance of the full morphological disambiguation task. However, as the size of resources increase, the value of the morphological analyzers decreases.

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A Spelling Correction Corpus for Multiple Arabic Dialects
Fadhl Eryani | Nizar Habash | Houda Bouamor | Salam Khalifa
Proceedings of the 12th Language Resources and Evaluation Conference

Arabic dialects are the non-standard varieties of Arabic commonly spoken – and increasingly written on social media – across the Arab world. Arabic dialects do not have standard orthographies, a challenge for natural language processing applications. In this paper, we present the MADAR CODA Corpus, a collection of 10,000 sentences from five Arabic city dialects (Beirut, Cairo, Doha, Rabat, and Tunis) represented in the Conventional Orthography for Dialectal Arabic (CODA) in parallel with their raw original form. The sentences come from the Multi-Arabic Dialect Applications and Resources (MADAR) Project and are in parallel across the cities (2,000 sentences from each city). This publicly available resource is intended to support research on spelling correction and text normalization for Arabic dialects. We present results on a bootstrapping technique we use to speed up the CODA annotation, as well as on the degree of similarity across the dialects before and after CODA annotation.

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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 12th 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.

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The Paradigm Discovery Problem
Alexander Erdmann | Micha Elsner | Shijie Wu | Ryan Cotterell | Nizar Habash
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

This work treats the paradigm discovery problem (PDP), the task of learning an inflectional morphological system from unannotated sentences. We formalize the PDP and develop evaluation metrics for judging systems. Using currently available resources, we construct datasets for the task. We also devise a heuristic benchmark for the PDP and report empirical results on five diverse languages. Our benchmark system first makes use of word embeddings and string similarity to cluster forms by cell and by paradigm. Then, we bootstrap a neural transducer on top of the clustered data to predict words to realize the empty paradigm slots. An error analysis of our system suggests clustering by cell across different inflection classes is the most pressing challenge for future work.

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Joint Diacritization, Lemmatization, Normalization, and Fine-Grained Morphological Tagging
Nasser Zalmout | Nizar Habash
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

The written forms of Semitic languages are both highly ambiguous and morphologically rich: a word can have multiple interpretations and is one of many inflected forms of the same concept or lemma. This is further exacerbated for dialectal content, which is more prone to noise and lacks a standard orthography. The morphological features can be lexicalized, like lemmas and diacritized forms, or non-lexicalized, like gender, number, and part-of-speech tags, among others. Joint modeling of the lexicalized and non-lexicalized features can identify more intricate morphological patterns, which provide better context modeling, and further disambiguate ambiguous lexical choices. However, the different modeling granularity can make joint modeling more difficult. Our approach models the different features jointly, whether lexicalized (on the character-level), or non-lexicalized (on the word-level). We use Arabic as a test case, and achieve state-of-the-art results for Modern Standard Arabic with 20% relative error reduction, and Egyptian Arabic with 11% relative error reduction.

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Gender-Aware Reinflection using Linguistically Enhanced Neural Models
Bashar Alhafni | Nizar Habash | Houda Bouamor
Proceedings of the Second Workshop on Gender Bias in Natural Language Processing

In this paper, we present an approach for sentence-level gender reinflection using linguistically enhanced sequence-to-sequence models. Our system takes an Arabic sentence and a given target gender as input and generates a gender-reinflected sentence based on the target gender. We formulate the problem as a user-aware grammatical error correction task and build an encoder-decoder architecture to jointly model reinflection for both masculine and feminine grammatical genders. We also show that adding linguistic features to our model leads to better reinflection results. The results on a blind test set using our best system show improvements over previous work, with a 3.6% absolute increase in M2 F0.5.

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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.

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NADI 2020: The First Nuanced Arabic Dialect Identification Shared Task
Muhammad Abdul-Mageed | Chiyu Zhang | Houda Bouamor | Nizar Habash
Proceedings of the Fifth Arabic Natural Language Processing Workshop

We present the results and findings of the First Nuanced Arabic Dialect Identification Shared Task (NADI). This Shared Task includes two subtasks: country-level dialect identification (Subtask 1) and province-level sub-dialect identification (Subtask 2). The data for the shared task covers a total of 100 provinces from 21 Arab countries and is collected from the Twitter domain. As such, NADI is the first shared task to target naturally-occurring fine-grained dialectal text at the sub-country level. A total of 61 teams from 25 countries registered to participate in the tasks, thus reflecting the interest of the community in this area. We received 47 submissions for Subtask 1 from 18 teams and 9 submissions for Subtask 2 from 9 teams.

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A Unified Model for Arabizi Detection and Transliteration using Sequence-to-Sequence Models
Ali Shazal | Aiza Usman | Nizar Habash
Proceedings of the Fifth Arabic Natural Language Processing Workshop

While online Arabic is primarily written using the Arabic script, a Roman-script variety called Arabizi is often seen on social media. Although this representation captures the phonology of the language, it is not a one-to-one mapping with the Arabic script version. This issue is exacerbated by the fact that Arabizi on social media is Dialectal Arabic which does not have a standard orthography. Furthermore, Arabizi tends to include a lot of code mixing between Arabic and English (or French). To map Arabizi text to Arabic script in the context of complete utterances, previously published efforts have split Arabizi detection and Arabic script target in two separate tasks. In this paper, we present the first effort on a unified model for Arabizi detection and transliteration into a code-mixed output with consistent Arabic spelling conventions, using a sequence-to-sequence deep learning model. Our best system achieves 80.6% word accuracy and 58.7% BLEU on a blind test set.

2019

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ADIDA: Automatic Dialect Identification for Arabic
Ossama Obeid | Mohammad Salameh | Houda Bouamor | Nizar Habash
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics (Demonstrations)

This demo paper describes ADIDA, a web-based system for automatic dialect identification for Arabic text. The system distinguishes among the dialects of 25 Arab cities (from Rabat to Muscat) in addition to Modern Standard Arabic. The results are presented with either a point map or a heat map visualizing the automatic identification probabilities over a geographical map of the Arab World.

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Automatic Gender Identification and Reinflection in Arabic
Nizar Habash | Houda Bouamor | Christine Chung
Proceedings of the First Workshop on Gender Bias in Natural Language Processing

The impressive progress in many Natural Language Processing (NLP) applications has increased the awareness of some of the biases these NLP systems have with regards to gender identities. In this paper, we propose an approach to extend biased single-output gender-blind NLP systems with gender-specific alternative reinflections. We focus on Arabic, a gender-marking morphologically rich language, in the context of machine translation (MT) from English, and for first-person-singular constructions only. Our contributions are the development of a system-independent gender-awareness wrapper, and the building of a corpus for training and evaluating first-person-singular gender identification and reinflection in Arabic. Our results successfully demonstrate the viability of this approach with 8% relative increase in Bleu score for first-person-singular feminine, and 5.3% comparable increase for first-person-singular masculine on top of a state-of-the-art gender-blind MT system on a held-out test set.

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A Little Linguistics Goes a Long Way: Unsupervised Segmentation with Limited Language Specific Guidance
Alexander Erdmann | Salam Khalifa | Mai Oudah | Nizar Habash | Houda Bouamor
Proceedings of the 16th Workshop on Computational Research in Phonetics, Phonology, and Morphology

We present de-lexical segmentation, a linguistically motivated alternative to greedy or other unsupervised methods, requiring only minimal language specific input. Our technique involves creating a small grammar of closed-class affixes which can be written in a few hours. The grammar over generates analyses for word forms attested in a raw corpus which are disambiguated based on features of the linguistic base proposed for each form. Extending the grammar to cover orthographic, morpho-syntactic or lexical variation is simple, making it an ideal solution for challenging corpora with noisy, dialect-inconsistent, or otherwise non-standard content. In two evaluations, we consistently outperform competitive unsupervised baselines and approach the performance of state-of-the-art supervised models trained on large amounts of data, providing evidence for the value of linguistic input during preprocessing.

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Morphologically Annotated Corpora for Seven Arabic Dialects: Taizi, Sanaani, Najdi, Jordanian, Syrian, Iraqi and Moroccan
Faisal Alshargi | Shahd Dibas | Sakhar Alkhereyf | Reem Faraj | Basmah Abdulkareem | Sane Yagi | Ouafaa Kacha | Nizar Habash | Owen Rambow
Proceedings of the Fourth Arabic Natural Language Processing Workshop

We present a collection of morphologically annotated corpora for seven Arabic dialects: Taizi Yemeni, Sanaani Yemeni, Najdi, Jordanian, Syrian, Iraqi and Moroccan Arabic. The corpora collectively cover over 200,000 words, and are all manually annotated in a common set of standards for orthography, diacritized lemmas, tokenization, morphological units and English glosses. These corpora will be publicly available to serve as benchmarks for training and evaluating systems for Arabic dialect morphological analysis and disambiguation.

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The MADAR Shared Task on Arabic Fine-Grained Dialect Identification
Houda Bouamor | Sabit Hassan | Nizar Habash
Proceedings of the Fourth Arabic Natural Language Processing Workshop

In this paper, we present the results and findings of the MADAR Shared Task on Arabic Fine-Grained Dialect Identification. This shared task was organized as part of The Fourth Arabic Natural Language Processing Workshop, collocated with ACL 2019. The shared task includes two subtasks: the MADAR Travel Domain Dialect Identification subtask (Subtask 1) and the MADAR Twitter User Dialect Identification subtask (Subtask 2). This shared task is the first to target a large set of dialect labels at the city and country levels. The data for the shared task was created or collected under the Multi-Arabic Dialect Applications and Resources (MADAR) project. A total of 21 teams from 15 countries participated in the shared task.

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The Impact of Preprocessing on Arabic-English Statistical and Neural Machine Translation
Mai Oudah | Amjad Almahairi | Nizar Habash
Proceedings of Machine Translation Summit XVII: Research Track

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Adversarial Multitask Learning for Joint Multi-Feature and Multi-Dialect Morphological Modeling
Nasser Zalmout | Nizar Habash
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

Morphological tagging is challenging for morphologically rich languages due to the large target space and the need for more training data to minimize model sparsity. Dialectal variants of morphologically rich languages suffer more as they tend to be more noisy and have less resources. In this paper we explore the use of multitask learning and adversarial training to address morphological richness and dialectal variations in the context of full morphological tagging. We use multitask learning for joint morphological modeling for the features within two dialects, and as a knowledge-transfer scheme for cross-dialectal modeling. We use adversarial training to learn dialect invariant features that can help the knowledge-transfer scheme from the high to low-resource variants. We work with two dialectal variants: Modern Standard Arabic (high-resource “dialect’”) and Egyptian Arabic (low-resource dialect) as a case study. Our models achieve state-of-the-art results for both. Furthermore, adversarial training provides more significant improvement when using smaller training datasets in particular.

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The Effectiveness of Simple Hybrid Systems for Hypernym Discovery
William Held | Nizar Habash
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

Hypernymy modeling has largely been separated according to two paradigms, pattern-based methods and distributional methods. However, recent works utilizing a mix of these strategies have yielded state-of-the-art results. This paper evaluates the contribution of both paradigms to hybrid success by evaluating the benefits of hybrid treatment of baseline models from each paradigm. Even with a simple methodology for each individual system, utilizing a hybrid approach establishes new state-of-the-art results on two domain-specific English hypernym discovery tasks and outperforms all non-hybrid approaches in a general English hypernym discovery task.

2018

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Fine-Grained Arabic Dialect Identification
Mohammad Salameh | Houda Bouamor | Nizar Habash
Proceedings of the 27th International Conference on Computational Linguistics

Previous work on the problem of Arabic Dialect Identification typically targeted coarse-grained five dialect classes plus Standard Arabic (6-way classification). This paper presents the first results on a fine-grained dialect classification task covering 25 specific cities from across the Arab World, in addition to Standard Arabic – a very challenging task. We build several classification systems and explore a large space of features. Our results show that we can identify the exact city of a speaker at an accuracy of 67.9% for sentences with an average length of 7 words (a 9% relative error reduction over the state-of-the-art technique for Arabic dialect identification) and reach more than 90% when we consider 16 words. We also report on additional insights from a data analysis of similarity and difference across Arabic dialects.

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A Cross-lingual Messenger with Keyword Searchable Phrases for the Travel Domain
Shehroze Khan | Jihyun Kim | Tarik Zulfikarpasic | Peter Chen | Nizar Habash
Proceedings of the 27th International Conference on Computational Linguistics: System Demonstrations

We present Qutr (Query Translator), a smart cross-lingual communication application for the travel domain. Qutr is a real-time messaging app that automatically translates conversations while supporting keyword-to-sentence matching. Qutr relies on querying a database that holds commonly used pre-translated travel-domain phrases and phrase templates in different languages with the use of keywords. The query matching supports paraphrases, incomplete keywords and some input spelling errors. The application addresses common cross-lingual communication issues such as translation accuracy, speed, privacy, and personalization.

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Noise-Robust Morphological Disambiguation for Dialectal Arabic
Nasser Zalmout | Alexander Erdmann | Nizar Habash
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers)

User-generated text tends to be noisy with many lexical and orthographic inconsistencies, making natural language processing (NLP) tasks more challenging. The challenging nature of noisy text processing is exacerbated for dialectal content, where in addition to spelling and lexical differences, dialectal text is characterized with morpho-syntactic and phonetic variations. These issues increase sparsity in NLP models and reduce accuracy. We present a neural morphological tagging and disambiguation model for Egyptian Arabic, with various extensions to handle noisy and inconsistent content. Our models achieve about 5% relative error reduction (1.1% absolute improvement) for full morphological analysis, and around 22% relative error reduction (1.8% absolute improvement) for part-of-speech tagging, over a state-of-the-art baseline.

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A Parallel Corpus of Arabic-Japanese News Articles
Go Inoue | Nizar Habash | Yuji Matsumoto | Hiroyuki Aoyama
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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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)

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A Leveled Reading Corpus of Modern Standard Arabic
Muhamed Al Khalil | Hind Saddiki | Nizar Habash | Latifa Alfalasi
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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MADARi: A Web Interface for Joint Arabic Morphological Annotation and Spelling Correction
Ossama Obeid | Salam Khalifa | Nizar Habash | Houda Bouamor | Wajdi Zaghouani | Kemal Oflazer
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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The MADAR Arabic Dialect Corpus and Lexicon
Houda Bouamor | Nizar Habash | Mohammad Salameh | Wajdi Zaghouani | Owen Rambow | Dana Abdulrahim | Ossama Obeid | Salam Khalifa | Fadhl Eryani | Alexander Erdmann | Kemal Oflazer
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Unified Guidelines and Resources for Arabic Dialect Orthography
Nizar Habash | Fadhl Eryani | Salam Khalifa | Owen Rambow | Dana Abdulrahim | Alexander Erdmann | Reem Faraj | Wajdi Zaghouani | Houda Bouamor | Nasser Zalmout | Sara Hassan | Faisal Al-Shargi | Sakhar Alkhereyf | Basma Abdulkareem | Ramy Eskander | Mohammad Salameh | Hind Saddiki
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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A Morphologically Annotated Corpus of Emirati Arabic
Salam Khalifa | Nizar Habash | Fadhl Eryani | Ossama Obeid | Dana Abdulrahim | Meera Al Kaabi
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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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)

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Addressing Noise in Multidialectal Word Embeddings
Alexander Erdmann | Nasser Zalmout | Nizar Habash
Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

Word embeddings are crucial to many natural language processing tasks. The quality of embeddings relies on large non-noisy corpora. Arabic dialects lack large corpora and are noisy, being linguistically disparate with no standardized spelling. We make three contributions to address this noise. First, we describe simple but effective adaptations to word embedding tools to maximize the informative content leveraged in each training sentence. Second, we analyze methods for representing disparate dialects in one embedding space, either by mapping individual dialects into a shared space or learning a joint model of all dialects. Finally, we evaluate via dictionary induction, showing that two metrics not typically reported in the task enable us to analyze our contributions’ effects on low and high frequency words. In addition to boosting performance between 2-53%, we specifically improve on noisy, low frequency forms without compromising accuracy on high frequency forms.

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Feature Optimization for Predicting Readability of Arabic L1 and L2
Hind Saddiki | Nizar Habash | Violetta Cavalli-Sforza | Muhamed Al Khalil
Proceedings of the 5th Workshop on Natural Language Processing Techniques for Educational Applications

Advances in automatic readability assessment can impact the way people consume information in a number of domains. Arabic, being a low-resource and morphologically complex language, presents numerous challenges to the task of automatic readability assessment. In this paper, we present the largest and most in-depth computational readability study for Arabic to date. We study a large set of features with varying depths, from shallow words to syntactic trees, for both L1 and L2 readability tasks. Our best L1 readability accuracy result is 94.8% (75% error reduction from a commonly used baseline). The comparable results for L2 are 72.4% (45% error reduction). We also demonstrate the added value of leveraging L1 features for L2 readability prediction.

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Improving Domain Independent Question Parsing with Synthetic Treebanks
Halim-Antoine Boukaram | Nizar Habash | Micheline Ziadee | Majd Sakr
Proceedings of the Joint Workshop on Linguistic Annotation, Multiword Expressions and Constructions (LAW-MWE-CxG-2018)

Automatic syntactic parsing for question constructions is a challenging task due to the paucity of training examples in most treebanks. The near absence of question constructions is due to the dominance of the news domain in treebanking efforts. In this paper, we compare two synthetic low-cost question treebank creation methods with a conventional manual high-cost annotation method in the context of three domains (news questions, political talk shows, and chatbots) for Modern Standard Arabic, a language with relatively low resources and rich morphology. Our results show that synthetic methods can be effective at significantly reducing parsing errors for a target domain without having to invest large resources on manual annotation; and the combination of manual and synthetic methods is our best domain-independent performer.

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A Bilingual Interactive Human Avatar Dialogue System
Dana Abu Ali | Muaz Ahmad | Hayat Al Hassan | Paula Dozsa | Ming Hu | Jose Varias | Nizar Habash
Proceedings of the 19th Annual SIGdial Meeting on Discourse and Dialogue

This demonstration paper presents a bilingual (Arabic-English) interactive human avatar dialogue system. The system is named TOIA (time-offset interaction application), as it simulates face-to-face conversations between humans using digital human avatars recorded in the past. TOIA is a conversational agent, similar to a chat bot, except that it is based on an actual human being and can be used to preserve and tell stories. The system is designed to allow anybody, simply using a laptop, to create an avatar of themselves, thus facilitating cross-cultural and cross-generational sharing of narratives to wider audiences. The system currently supports monolingual and cross-lingual dialogues in Arabic and English, but can be extended to other languages.

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Complementary Strategies for Low Resourced Morphological Modeling
Alexander Erdmann | Nizar Habash
Proceedings of the Fifteenth Workshop on Computational Research in Phonetics, Phonology, and Morphology

Morphologically rich languages are challenging for natural language processing tasks due to data sparsity. This can be addressed either by introducing out-of-context morphological knowledge, or by developing machine learning architectures that specifically target data sparsity and/or morphological information. We find these approaches to complement each other in a morphological paradigm modeling task in Modern Standard Arabic, which, in addition to being morphologically complex, features ubiquitous ambiguity, exacerbating sparsity with noise. Given a small number of out-of-context rules describing closed class morphology, we combine them with word embeddings leveraging subword strings and noise reduction techniques. The combination outperforms both approaches individually by about 20% absolute. While morphological resources already exist for Modern Standard Arabic, our results inform how comparable resources might be constructed for non-standard dialects or any morphologically rich, low resourced language, given scarcity of time and funding.

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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.

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Utilizing Character and Word Embeddings for Text Normalization with Sequence-to-Sequence Models
Daniel Watson | Nasser Zalmout | Nizar Habash
Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing

Text normalization is an important enabling technology for several NLP tasks. Recently, neural-network-based approaches have outperformed well-established models in this task. However, in languages other than English, there has been little exploration in this direction. Both the scarcity of annotated data and the complexity of the language increase the difficulty of the problem. To address these challenges, we use a sequence-to-sequence model with character-based attention, which in addition to its self-learned character embeddings, uses word embeddings pre-trained with an approach that also models subword information. This provides the neural model with access to more linguistic information especially suitable for text normalization, without large parallel corpora. We show that providing the model with word-level features bridges the gap for the neural network approach to achieve a state-of-the-art F1 score on a standard Arabic language correction shared task dataset.

2017

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Proceedings of the Third Arabic Natural Language Processing Workshop
Nizar Habash | Mona Diab | Kareem Darwish | Wassim El-Hajj | Hend Al-Khalifa | Houda Bouamor | Nadi Tomeh | Mahmoud El-Haj
Proceedings of the Third Arabic Natural Language Processing Workshop

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A Morphological Analyzer for Gulf Arabic Verbs
Salam Khalifa | Sara Hassan | Nizar Habash
Proceedings of the Third Arabic Natural Language Processing Workshop

We present CALIMAGLF, a Gulf Arabic morphological analyzer currently covering over 2,600 verbal lemmas. We describe in detail the process of building the analyzer starting from phonetic dictionary entries to fully inflected orthographic paradigms and associated lexicon and orthographic variants. We evaluate the coverage of CALIMA-GLF against Modern Standard Arabic and Egyptian Arabic analyzers on part of a Gulf Arabic novel. CALIMA-GLF verb analysis token recall for identifying correct POS tag outperforms both the Modern Standard Arabic and Egyptian Arabic analyzers by over 27.4% and 16.9% absolute, respectively.

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A Characterization Study of Arabic Twitter Data with a Benchmarking for State-of-the-Art Opinion Mining Models
Ramy Baly | Gilbert Badaro | Georges El-Khoury | Rawan Moukalled | Rita Aoun | Hazem Hajj | Wassim El-Hajj | Nizar Habash | Khaled Shaban
Proceedings of the Third Arabic Natural Language Processing Workshop

Opinion mining in Arabic is a challenging task given the rich morphology of the language. The task becomes more challenging when it is applied to Twitter data, which contains additional sources of noise, such as the use of unstandardized dialectal variations, the nonconformation to grammatical rules, the use of Arabizi and code-switching, and the use of non-text objects such as images and URLs to express opinion. In this paper, we perform an analytical study to observe how such linguistic phenomena vary across different Arab regions. This study of Arabic Twitter characterization aims at providing better understanding of Arabic Tweets, and fostering advanced research on the topic. Furthermore, we explore the performance of the two schools of machine learning on Arabic Twitter, namely the feature engineering approach and the deep learning approach. We consider models that have achieved state-of-the-art performance for opinion mining in English. Results highlight the advantages of using deep learning-based models, and confirm the importance of using morphological abstractions to address Arabic’s complex morphology.

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Robust Dictionary Lookup in Multiple Noisy Orthographies
Lingliang Zhang | Nizar Habash | Godfried Toussaint
Proceedings of the Third Arabic Natural Language Processing Workshop

We present the MultiScript Phonetic Search algorithm to address the problem of language learners looking up unfamiliar words that they heard. We apply it to Arabic dictionary lookup with noisy queries done using both the Arabic and Roman scripts. Our algorithm is based on a computational phonetic distance metric that can be optionally machine learned. To benchmark our performance, we created the ArabScribe dataset, containing 10,000 noisy transcriptions of random Arabic dictionary words. Our algorithm outperforms Google Translate’s “did you mean” feature, as well as the Yamli smart Arabic keyboard.

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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.

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OMAM at SemEval-2017 Task 4: Evaluation of English State-of-the-Art Sentiment Analysis Models for Arabic and a New Topic-based Model
Ramy Baly | Gilbert Badaro | Ali Hamdi | Rawan Moukalled | Rita Aoun | Georges El-Khoury | Ahmad Al Sallab | Hazem Hajj | Nizar Habash | Khaled Shaban | Wassim El-Hajj
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

While sentiment analysis in English has achieved significant progress, it remains a challenging task in Arabic given the rich morphology of the language. It becomes more challenging when applied to Twitter data that comes with additional sources of noise including dialects, misspellings, grammatical mistakes, code switching and the use of non-textual objects to express sentiments. This paper describes the “OMAM” systems that we developed as part of SemEval-2017 task 4. We evaluate English state-of-the-art methods on Arabic tweets for subtask A. As for the remaining subtasks, we introduce a topic-based approach that accounts for topic specificities by predicting topics or domains of upcoming tweets, and then using this information to predict their sentiment. Results indicate that applying the English state-of-the-art method to Arabic has achieved solid results without significant enhancements. Furthermore, the topic-based method ranked 1st in subtasks C and E, and 2nd in subtask D.

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OMAM at SemEval-2017 Task 4: English Sentiment Analysis with Conditional Random Fields
Chukwuyem Onyibe | Nizar Habash
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

We describe a supervised system that uses optimized Condition Random Fields and lexical features to predict the sentiment of a tweet. The system was submitted to the English version of all subtasks in SemEval-2017 Task 4.

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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.

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Don’t Throw Those Morphological Analyzers Away Just Yet: Neural Morphological Disambiguation for Arabic
Nasser Zalmout | Nizar Habash
Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing

This paper presents a model for Arabic morphological disambiguation based on Recurrent Neural Networks (RNN). We train Long Short-Term Memory (LSTM) cells in several configurations and embedding levels to model the various morphological features. Our experiments show that these models outperform state-of-the-art systems without explicit use of feature engineering. However, adding learning features from a morphological analyzer to model the space of possible analyses provides additional improvement. We make use of the resulting morphological models for scoring and ranking the analyses of the morphological analyzer for morphological disambiguation. The results show significant gains in accuracy across several evaluation metrics. Our system results in 4.4% absolute increase over the state-of-the-art in full morphological analysis accuracy (30.6% relative error reduction), and 10.6% (31.5% relative error reduction) for out-of-vocabulary words.

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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.

2016

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DALILA: The Dialectal Arabic Linguistic Learning Assistant
Salam Khalifa | Houda Bouamor | Nizar Habash
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Dialectal Arabic (DA) poses serious challenges for Natural Language Processing (NLP). The number and sophistication of tools and datasets in DA are very limited in comparison to Modern Standard Arabic (MSA) and other languages. MSA tools do not effectively model DA which makes the direct use of MSA NLP tools for handling dialects impractical. This is particularly a challenge for the creation of tools to support learning Arabic as a living language on the web, where authentic material can be found in both MSA and DA. In this paper, we present the Dialectal Arabic Linguistic Learning Assistant (DALILA), a Chrome extension that utilizes cutting-edge Arabic dialect NLP research to assist learners and non-native speakers in understanding text written in either MSA or DA. DALILA provides dialectal word analysis and English gloss corresponding to each word.

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Morphologically Annotated Corpora and Morphological Analyzers for Moroccan and Sanaani Yemeni Arabic
Faisal Al-Shargi | Aidan Kaplan | Ramy Eskander | Nizar Habash | Owen Rambow
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

We present new language resources for Moroccan and Sanaani Yemeni Arabic. The resources include corpora for each dialect which have been morphologically annotated, and morphological analyzers for each dialect which are derived from these corpora. These are the first sets of resources for Moroccan and Yemeni Arabic. The resources will be made available to the public.

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Building an Arabic Machine Translation Post-Edited Corpus: Guidelines and Annotation
Wajdi Zaghouani | Nizar Habash | Ossama Obeid | Behrang Mohit | Houda Bouamor | Kemal Oflazer
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

We present our guidelines and annotation procedure to create a human corrected machine translated post-edited corpus for the Modern Standard Arabic. Our overarching goal is to use the annotated corpus to develop automatic machine translation post-editing systems for Arabic that can be used to help accelerate the human revision process of translated texts. The creation of any manually annotated corpus usually presents many challenges. In order to address these challenges, we created comprehensive and simplified annotation guidelines which were used by a team of five annotators and one lead annotator. In order to ensure a high annotation agreement between the annotators, multiple training sessions were held and regular inter-annotator agreement measures were performed to check the annotation quality. The created corpus of manual post-edited translations of English to Arabic articles is the largest to date for this language pair.

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Applying the Cognitive Machine Translation Evaluation Approach to Arabic
Irina Temnikova | Wajdi Zaghouani | Stephan Vogel | Nizar Habash
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

The goal of the cognitive machine translation (MT) evaluation approach is to build classifiers which assign post-editing effort scores to new texts. The approach helps estimate fair compensation for post-editors in the translation industry by evaluating the cognitive difficulty of post-editing MT output. The approach counts the number of errors classified in different categories on the basis of how much cognitive effort they require in order to be corrected. In this paper, we present the results of applying an existing cognitive evaluation approach to Modern Standard Arabic (MSA). We provide a comparison of the number of errors and categories of errors in three MSA texts of different MT quality (without any language-specific adaptation), as well as a comparison between MSA texts and texts from three Indo-European languages (Russian, Spanish, and Bulgarian), taken from a previous experiment. The results show how the error distributions change passing from the MSA texts of worse MT quality to MSA texts of better MT quality, as well as a similarity in distinguishing the texts of better MT quality for all four languages.

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SPLIT: Smart Preprocessing (Quasi) Language Independent Tool
Mohamed Al-Badrashiny | Arfath Pasha | Mona Diab | Nizar Habash | Owen Rambow | Wael Salloum | Ramy Eskander
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Text preprocessing is an important and necessary task for all NLP applications. A simple variation in any preprocessing step may drastically affect the final results. Moreover replicability and comparability, as much as feasible, is one of the goals of our scientific enterprise, thus building systems that can ensure the consistency in our various pipelines would contribute significantly to our goals. The problem has become quite pronounced with the abundance of NLP tools becoming more and more available yet with different levels of specifications. In this paper, we present a dynamic unified preprocessing framework and tool, SPLIT, that is highly configurable based on user requirements which serves as a preprocessing tool for several tools at once. SPLIT aims to standardize the implementations of the most important preprocessing steps by allowing for a unified API that could be exchanged across different researchers to ensure complete transparency in replication. The user is able to select the required preprocessing tasks among a long list of preprocessing steps. The user is also able to specify the order of execution which in turn affects the final preprocessing output.

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A Large Scale Corpus of Gulf Arabic
Salam Khalifa | Nizar Habash | Dana Abdulrahim | Sara Hassan
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Most Arabic natural language processing tools and resources are developed to serve Modern Standard Arabic (MSA), which is the official written language in the Arab World. Some Dialectal Arabic varieties, notably Egyptian Arabic, have received some attention lately and have a growing collection of resources that include annotated corpora and morphological analyzers and taggers. Gulf Arabic, however, lags behind in that respect. In this paper, we present the Gumar Corpus, a large-scale corpus of Gulf Arabic consisting of 110 million words from 1,200 forum novels. We annotate the corpus for sub-dialect information at the document level. We also present results of a preliminary study in the morphological annotation of Gulf Arabic which includes developing guidelines for a conventional orthography. The text of the corpus is publicly browsable through a web interface we developed for it.

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Exploiting Arabic Diacritization for High Quality Automatic Annotation
Nizar Habash | Anas Shahrour | Muhamed Al-Khalil
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

We present a novel technique for Arabic morphological annotation. The technique utilizes diacritization to produce morphological annotations of quality comparable to human annotators. Although Arabic text is generally written without diacritics, diacritization is already available for large corpora of Arabic text in several genres. Furthermore, diacritization can be generated at a low cost for new text as it does not require specialized training beyond what educated Arabic typists know. The basic approach is to enrich the input to a state-of-the-art Arabic morphological analyzer with word diacritics (full or partial) to enhance its performance. When applied to fully diacritized text, our approach produces annotations with an accuracy of over 97% on lemma, part-of-speech, and tokenization combined.

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Arabic Corpora for Credibility Analysis
Ayman Al Zaatari | Rim El Ballouli | Shady ELbassouni | Wassim El-Hajj | Hazem Hajj | Khaled Shaban | Nizar Habash | Emad Yahya
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

A significant portion of data generated on blogging and microblogging websites is non-credible as shown in many recent studies. To filter out such non-credible information, machine learning can be deployed to build automatic credibility classifiers. However, as in the case with most supervised machine learning approaches, a sufficiently large and accurate training data must be available. In this paper, we focus on building a public Arabic corpus of blogs and microblogs that can be used for credibility classification. We focus on Arabic due to the recent popularity of blogs and microblogs in the Arab World and due to the lack of any such public corpora in Arabic. We discuss our data acquisition approach and annotation process, provide rigid analysis on the annotated data and finally report some results on the effectiveness of our data for credibility classification.

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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

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Analysis of Foreign Language Teaching Methods: An Automatic Readability Approach
Nasser Zalmout | Hind Saddiki | Nizar Habash
Proceedings of the 3rd Workshop on Natural Language Processing Techniques for Educational Applications (NLPTEA2016)

Much research in education has been done on the study of different language teaching methods. However, there has been little investigation using computational analysis to compare such methods in terms of readability or complexity progression. In this paper, we make use of existing readability scoring techniques and our own classifiers to analyze the textbooks used in two very different teaching methods for English as a Second Language – the grammar-based and the communicative methods. Our analysis indicates that the grammar-based curriculum shows a more coherent readability progression compared to the communicative curriculum. This finding corroborates with the expectations about the differences between these two methods and validates our approach’s value in comparing different teaching methods quantitatively.

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Machine Translation Evaluation for Arabic using Morphologically-enriched Embeddings
Francisco Guzmán | Houda Bouamor | Ramy Baly | Nizar Habash
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers

Evaluation of machine translation (MT) into morphologically rich languages (MRL) has not been well studied despite posing many challenges. In this paper, we explore the use of embeddings obtained from different levels of lexical and morpho-syntactic linguistic analysis and show that they improve MT evaluation into an MRL. Specifically we report on Arabic, a language with complex and rich morphology. Our results show that using a neural-network model with different input representations produces results that clearly outperform the state-of-the-art for MT evaluation into Arabic, by almost over 75% increase in correlation with human judgments on pairwise MT evaluation quality task. More importantly, we demonstrate the usefulness of morpho-syntactic representations to model sentence similarity for MT evaluation and address complex linguistic phenomena of Arabic.

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Creating Resources for Dialectal Arabic from a Single Annotation: A Case Study on Egyptian and Levantine
Ramy Eskander | Nizar Habash | Owen Rambow | Arfath Pasha
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: Technical Papers

Arabic dialects present a special problem for natural language processing because there are few resources, they have no standard orthography, and have not been studied much. However, as more and more written dialectal Arabic is found in social media, NLP for Arabic dialects becomes an important goal. We present a methodology for creating a morphological analyzer and a morphological tagger for dialectal Arabic, and we illustrate it on Egyptian and Levantine Arabic. To our knowledge, these are the first analyzer and tagger for Levantine.

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Botta: An Arabic Dialect Chatbot
Dana Abu Ali | Nizar Habash
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: System Demonstrations

This paper presents BOTTA, the first Arabic dialect chatbot. We explore the challenges of creating a conversational agent that aims to simulate friendly conversations using the Egyptian Arabic dialect. We present a number of solutions and describe the different components of the BOTTA chatbot. The BOTTA database files are publicly available for researchers working on Arabic chatbot technologies. The BOTTA chatbot is also publicly available for any users who want to chat with it online.

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YAMAMA: Yet Another Multi-Dialect Arabic Morphological Analyzer
Salam Khalifa | Nasser Zalmout | Nizar Habash
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: System Demonstrations

In this paper, we present YAMAMA, a multi-dialect Arabic morphological analyzer and disambiguator. Our system is almost five times faster than the state-of-art MADAMIRA system with a slightly lower quality. In addition to speed, YAMAMA outputs a rich representation which allows for a wider spectrum of use. In this regard, YAMAMA transcends other systems, such as FARASA, which is faster but provides specific outputs catering to specific applications.

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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.

2015

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Predicting the Structure of Cooking Recipes
Jermsak Jermsurawong | Nizar Habash
Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing

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Improving Arabic Diacritization through Syntactic Analysis
Anas Shahrour | Salam Khalifa | Nizar Habash
Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing

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Correction Annotation for Non-Native Arabic Texts: Guidelines and Corpus
Wajdi Zaghouani | Nizar Habash | Houda Bouamor | Alla Rozovskaya | Behrang Mohit | Abeer Heider | Kemal Oflazer
Proceedings of The 9th Linguistic Annotation Workshop

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Proceedings of the Second Workshop on Arabic Natural Language Processing
Nizar Habash | Stephan Vogel | Kareem Darwish
Proceedings of the Second Workshop on Arabic Natural Language Processing

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The Second QALB Shared Task on Automatic Text Correction for Arabic
Alla Rozovskaya | Houda Bouamor | Nizar Habash | Wajdi Zaghouani | Ossama Obeid | Behrang Mohit
Proceedings of the Second Workshop on Arabic Natural Language Processing

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POS-tagging of Tunisian Dialect Using Standard Arabic Resources and Tools
Ahmed Hamdi | Alexis Nasr | Nizar Habash | Núria Gala
Proceedings of the Second Workshop on Arabic Natural Language Processing

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A Conventional Orthography for Algerian Arabic
Houda Saadane | Nizar Habash
Proceedings of the Second Workshop on Arabic Natural Language Processing

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Annotating Targets of Opinions in Arabic using Crowdsourcing
Noura Farra | Kathy McKeown | Nizar Habash
Proceedings of the Second Workshop on Arabic Natural Language Processing

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Morphological constraints for phrase pivot statistical machine translation
Ahmed El Kholy | Nizar Habash
Proceedings of Machine Translation Summit XV: Papers

2014

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Automatic Transliteration of Romanized Dialectal Arabic
Mohamed Al-Badrashiny | Ramy Eskander | Nizar Habash | Owen Rambow
Proceedings of the Eighteenth Conference on Computational Natural Language Learning

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The Illinois-Columbia System in the CoNLL-2014 Shared Task
Alla Rozovskaya | Kai-Wei Chang | Mark Sammons | Dan Roth | Nizar Habash
Proceedings of the Eighteenth Conference on Computational Natural Language Learning: Shared Task

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Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)
Nizar Habash | Stephan Vogel
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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Building a Corpus for Palestinian Arabic: a Preliminary Study
Mustafa Jarrar | Nizar Habash | Diyam Akra | Nasser Zalmout
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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The First QALB Shared Task on Automatic Text Correction for Arabic
Behrang Mohit | Alla Rozovskaya | Nizar Habash | Wajdi Zaghouani | Ossama Obeid
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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Transliteration of Arabizi into Arabic Orthography: Developing a Parallel Annotated Arabizi-Arabic Script SMS/Chat Corpus
Ann Bies | Zhiyi Song | Mohamed Maamouri | Stephen Grimes | Haejoong Lee | Jonathan Wright | Stephanie Strassel | Nizar Habash | Ramy Eskander | Owen Rambow
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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A Pipeline Approach to Supervised Error Correction for the QALB-2014 Shared Task
Nadi Tomeh | Nizar Habash | Ramy Eskander | Joseph Le Roux
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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The Columbia System in the QALB-2014 Shared Task on Arabic Error Correction
Alla Rozovskaya | Nizar Habash | Ramy Eskander | Noura Farra | Wael Salloum
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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A Large Scale Arabic Sentiment Lexicon for Arabic Opinion Mining
Gilbert Badaro | Ramy Baly | Hazem Hajj | Nizar Habash | Wassim El-Hajj
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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Domain and Dialect Adaptation for Machine Translation into Egyptian Arabic
Serena Jeblee | Weston Feely | Houda Bouamor | Alon Lavie | Nizar Habash | Kemal Oflazer
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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Foreign Words and the Automatic Processing of Arabic Social Media Text Written in Roman Script
Ramy Eskander | Mohamed Al-Badrashiny | Nizar Habash | Owen Rambow
Proceedings of the First Workshop on Computational Approaches to Code Switching

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INVITED TALK 1: Computational Processing of Arabic Dialects
Nizar Habash
Proceedings of the EMNLP’2014 Workshop on Language Technology for Closely Related Languages and Language Variants

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Developing an Egyptian Arabic Treebank: Impact of Dialectal Morphology on Annotation and Tool Development
Mohamed Maamouri | Ann Bies | Seth Kulick | Michael Ciul | Nizar Habash | Ramy Eskander
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

This paper describes the parallel development of an Egyptian Arabic Treebank and a morphological analyzer for Egyptian Arabic (CALIMA). By the very nature of Egyptian Arabic, the data collected is informal, for example Discussion Forum text, which we use for the treebank discussed here. In addition, Egyptian Arabic, like other Arabic dialects, is sufficiently different from Modern Standard Arabic (MSA) that tools and techniques developed for MSA cannot be simply transferred over to work on Egyptian Arabic work. In particular, a morphological analyzer for Egyptian Arabic is needed to mediate between the written text and the segmented, vocalized form used for the syntactic trees. This led to the necessity of a feedback loop between the treebank team and the analyzer team, as improvements in each area were fed to the other. Therefore, by necessity, there needed to be close cooperation between the annotation team and the tool development team, which was to their mutual benefit. Collaboration on this type of challenge, where tools and resources are limited, proved to be remarkably synergistic and opens the way to further fruitful work on Arabic dialects.

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Tharwa: A Large Scale Dialectal Arabic - Standard Arabic - English Lexicon
Mona Diab | Mohamed Al-Badrashiny | Maryam Aminian | Mohammed Attia | Heba Elfardy | Nizar Habash | Abdelati Hawwari | Wael Salloum | Pradeep Dasigi | Ramy Eskander
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

We introduce an electronic three-way lexicon, Tharwa, comprising Dialectal Arabic, Modern Standard Arabic and English correspondents. The paper focuses on Egyptian Arabic as the first pilot dialect for the resource, with plans to expand to other dialects of Arabic in later phases of the project. We describe Tharwa’s creation process and report on its current status. The lexical entries are augmented with various elements of linguistic information such as POS, gender, rationality, number, and root and pattern information. The lexicon is based on a compilation of information from both monolingual and bilingual existing resources such as paper dictionaries and electronic, corpus-based dictionaries. Multiple levels of quality checks are performed on the output of each step in the creation process. The importance of this lexicon lies in the fact that it is the first resource of its kind bridging multiple variants of Arabic with English. Furthermore, it is a wide coverage lexical resource containing over 73,000 Egyptian entries. Tharwa is publicly available. We believe it will have a significant impact on both Theoretical Linguistics as well as Computational Linguistics research.

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A Conventional Orthography for Tunisian Arabic
Inès Zribi | Rahma Boujelbane | Abir Masmoudi | Mariem Ellouze | Lamia Belguith | Nizar Habash
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

Tunisian Arabic is a dialect of the Arabic language spoken in Tunisia. Tunisian Arabic is an under-resourced language. It has neither a standard orthography nor large collections of written text and dictionaries. Actually, there is no strict separation between Modern Standard Arabic, the official language of the government, media and education, and Tunisian Arabic; the two exist on a continuum dominated by mixed forms. In this paper, we present a conventional orthography for Tunisian Arabic, following a previous effort on developing a conventional orthography for Dialectal Arabic (or CODA) demonstrated for Egyptian Arabic. We explain the design principles of CODA and provide a detailed description of its guidelines as applied to Tunisian Arabic.

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A Corpus and Phonetic Dictionary for Tunisian Arabic Speech Recognition
Abir Masmoudi | Mariem Ellouze Khmekhem | Yannick Estève | Lamia Hadrich Belguith | Nizar Habash
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

In this paper we describe an effort to create a corpus and phonetic dictionary for Tunisian Arabic Automatic Speech Recognition (ASR). The corpus, named TARIC (Tunisian Arabic Railway Interaction Corpus) has a collection of audio recordings and transcriptions from dialogues in the Tunisian Railway Transport Network. The phonetic (or pronunciation) dictionary is an important ASR component that serves as an intermediary between acoustic models and language models in ASR systems. The method proposed in this paper, to automatically generate a phonetic dictionary, is rule based. For that reason, we define a set of pronunciation rules and a lexicon of exceptions. To determine the performance of our phonetic rules, we chose to evaluate our pronunciation dictionary on two types of corpora. The word error rate of word grapheme-to-phoneme mapping is around 9%.

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A Multidialectal Parallel Corpus of Arabic
Houda Bouamor | Nizar Habash | Kemal Oflazer
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

The daily spoken variety of Arabic is often termed the colloquial or dialect form of Arabic. There are many Arabic dialects across the Arab World and within other Arabic speaking communities. These dialects vary widely from region to region and to a lesser extent from city to city in each region. The dialects are not standardized, they are not taught, and they do not have official status. However they are the primary vehicles of communication (face-to-face and recently, online) and have a large presence in the arts as well. In this paper, we present the first multidialectal Arabic parallel corpus, a collection of 2,000 sentences in Standard Arabic, Egyptian, Tunisian, Jordanian, Palestinian and Syrian Arabic, in addition to English. Such parallel data does not exist naturally, which makes this corpus a very valuable resource that has many potential applications such as Arabic dialect identification and machine translation.

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MADAMIRA: A Fast, Comprehensive Tool for Morphological Analysis and Disambiguation of Arabic
Arfath Pasha | Mohamed Al-Badrashiny | Mona Diab | Ahmed El Kholy | Ramy Eskander | Nizar Habash | Manoj Pooleery | Owen Rambow | Ryan Roth
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

In this paper, we present MADAMIRA, a system for morphological analysis and disambiguation of Arabic that combines some of the best aspects of two previously commonly used systems for Arabic processing, MADA (Habash and Rambow, 2005; Habash et al., 2009; Habash et al., 2013) and AMIRA (Diab et al., 2007). MADAMIRA improves upon the two systems with a more streamlined Java implementation that is more robust, portable, extensible, and is faster than its ancestors by more than an order of magnitude. We also discuss an online demo (see http://nlp.ldeo.columbia.edu/madamira/) that highlights these aspects.

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Large Scale Arabic Error Annotation: Guidelines and Framework
Wajdi Zaghouani | Behrang Mohit | Nizar Habash | Ossama Obeid | Nadi Tomeh | Alla Rozovskaya | Noura Farra | Sarah Alkuhlani | Kemal Oflazer
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

We present annotation guidelines and a web-based annotation framework developed as part of an effort to create a manually annotated Arabic corpus of errors and corrections for various text types. Such a corpus will be invaluable for developing Arabic error correction tools, both for training models and as a gold standard for evaluating error correction algorithms. We summarize the guidelines we created. We also describe issues encountered during the training of the annotators, as well as problems that are specific to the Arabic language that arose during the annotation process. Finally, we present the annotation tool that was developed as part of this project, the annotation pipeline, and the quality of the resulting annotations.

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Natural Language Processing of Arabic and its Dialects
Mona Diab | Nizar Habash
Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing: Tutorial Abstracts

This tutorial introduces the different challenges and current solutions to the automatic processing of Arabic and its dialects. The tutorial has two parts: First, we present a discussion of generic issues relevant to Arabic NLP and detail dialectal linguistic issues and the challenges they pose for NLP. In the second part, we review the state-of-the-art in Arabic processing covering several enabling technologies and applications, e.g., dialect identification, morphological processing (analysis, disambiguation, tokenization, POS tagging), parsing, and machine translation.

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Alignment symmetrisation optimization targeting phrase pivot statistical machine translation
Ahmed El Kholy | Nizar Habash
Proceedings of the 17th Annual conference of the European Association for Machine Translation

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Unsupervised Morphology-Based Vocabulary Expansion
Mohammad Sadegh Rasooli | Thomas Lippincott | Nizar Habash | Owen Rambow
Proceedings of the 52nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

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Generalized Character-Level Spelling Error Correction
Noura Farra | Nadi Tomeh | Alla Rozovskaya | Nizar Habash
Proceedings of the 52nd Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

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Sentence Level Dialect Identification for Machine Translation System Selection
Wael Salloum | Heba Elfardy | Linda Alamir-Salloum | Nizar Habash | Mona Diab
Proceedings of the 52nd Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

2013

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Automatic Extraction of Morphological Lexicons from Morphologically Annotated Corpora
Ramy Eskander | Nizar Habash | Owen Rambow
Proceedings of the 2013 Conference on Empirical Methods in Natural Language Processing

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Orthographic and Morphological Processing for Persian-to-English Statistical Machine Translation
Mohammad Sadegh Rasooli | Ahmed El Kholy | Nizar Habash
Proceedings of the Sixth International Joint Conference on Natural Language Processing

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Selective Combination of Pivot and Direct Statistical Machine Translation Models
Ahmed El Kholy | Nizar Habash | Gregor Leusch | Evgeny Matusov | Hassan Sawaf
Proceedings of the Sixth International Joint Conference on Natural Language Processing

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A Web-based Annotation Framework For Large-Scale Text Correction
Ossama Obeid | Wajdi Zaghouani | Behrang Mohit | Nizar Habash | Kemal Oflazer | Nadi Tomeh
The Companion Volume of the Proceedings of IJCNLP 2013: System Demonstrations

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DIRA: Dialectal Arabic Information Retrieval Assistant
Arfath Pasha | Mohammad Al-Badrashiny | Mohamed Altantawy | Nizar Habash | Manoj Pooleery | Owen Rambow | Ryan M. Roth | Mona Diab
The Companion Volume of the Proceedings of IJCNLP 2013: System Demonstrations

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Dialectal Arabic to English Machine Translation: Pivoting through Modern Standard Arabic
Wael Salloum | Nizar Habash
Proceedings of the 2013 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Morphological Analysis and Disambiguation for Dialectal Arabic
Nizar Habash | Ryan Roth | Owen Rambow | Ramy Eskander | Nadi Tomeh
Proceedings of the 2013 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Automatic Morphological Enrichment of a Morphologically Underspecified Treebank
Sarah Alkuhlani | Nizar Habash | Ryan Roth
Proceedings of the 2013 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Processing Spontaneous Orthography
Ramy Eskander | Nizar Habash | Owen Rambow | Nadi Tomeh
Proceedings of the 2013 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Automatic Correction and Extension of Morphological Annotations
Ramy Eskander | Nizar Habash | Ann Bies | Seth Kulick | Mohamed Maamouri
Proceedings of the 7th Linguistic Annotation Workshop and Interoperability with Discourse

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SPMRL‘13 Shared Task System: The CADIM Arabic Dependency Parser
Yuval Marton | Nizar Habash | Owen Rambow | Sarah Alkhulani
Proceedings of the Fourth Workshop on Statistical Parsing of Morphologically-Rich Languages

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Overview of the SPMRL 2013 Shared Task: A Cross-Framework Evaluation of Parsing Morphologically Rich Languages
Djamé Seddah | Reut Tsarfaty | Sandra Kübler | Marie Candito | Jinho D. Choi | Richárd Farkas | Jennifer Foster | Iakes Goenaga | Koldo Gojenola Galletebeitia | Yoav Goldberg | Spence Green | Nizar Habash | Marco Kuhlmann | Wolfgang Maier | Joakim Nivre | Adam Przepiórkowski | Ryan Roth | Wolfgang Seeker | Yannick Versley | Veronika Vincze | Marcin Woliński | Alina Wróblewska | Eric Villemonte de la Clergerie
Proceedings of the Fourth Workshop on Statistical Parsing of Morphologically-Rich Languages

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Language Independent Connectivity Strength Features for Phrase Pivot Statistical Machine Translation
Ahmed El Kholy | Nizar Habash | Gregor Leusch | Evgeny Matusov | Hassan Sawaf
Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

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Reranking with Linguistic and Semantic Features for Arabic Optical Character Recognition
Nadi Tomeh | Nizar Habash | Ryan Roth | Noura Farra | Pradeep Dasigi | Mona Diab
Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

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The Effects of Factorizing Root and Pattern Mapping in Bidirectional Tunisian - Standard Arabic Machine Translation
Ahmed Hamdi | Rahma Boujelbane | Nizar Habash | Alexis Nasr
Proceedings of Machine Translation Summit XIV: Papers

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Dependency Parsing of Modern Standard Arabic with Lexical and Inflectional Features
Yuval Marton | Nizar Habash | Owen Rambow
Computational Linguistics, Volume 39, Issue 1 - March 2013

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Translating verbs between MSA and arabic dialects through deep morphological analysis (Un système de traduction de verbes entre arabe standard et arabe dialectal par analyse morphologique profonde) [in French]
Ahmed Hamdi | Rahma Boujelbane | Nizar Habash | Alexis Nasr
Proceedings of TALN 2013 (Volume 1: Long Papers)

2012

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Rich Morphology Generation Using Statistical Machine Translation
Ahmed El Kholy | Nizar Habash
INLG 2012 Proceedings of the Seventh International Natural Language Generation Conference

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A Morphological Analyzer for Egyptian Arabic
Nizar Habash | Ramy Eskander | Abdelati Hawwari
Proceedings of the Twelfth Meeting of the Special Interest Group on Computational Morphology and Phonology

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Conventional Orthography for Dialectal Arabic
Nizar Habash | Mona Diab | Owen Rambow
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

Dialectal Arabic (DA) refers to the day-to-day vernaculars spoken in the Arab world. DA lives side-by-side with the official language, Modern Standard Arabic (MSA). DA differs from MSA on all levels of linguistic representation, from phonology and morphology to lexicon and syntax. Unlike MSA, DA has no standard orthography since there are no Arabic dialect academies, nor is there a large edited body of dialectal literature that follows the same spelling standard. In this paper, we present CODA, a conventional orthography for dialectal Arabic; it is designed primarily for the purpose of developing computational models of Arabic dialects. We explain the design principles of CODA and provide a detailed description of its guidelines as applied to Egyptian Arabic.

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Elissa: A Dialectal to Standard Arabic Machine Translation System
Wael Salloum | Nizar Habash
Proceedings of COLING 2012: Demonstration Papers

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Translate, Predict or Generate: Modeling Rich Morphology in Statistical Machine Translation
Ahmed El Kholy | Nizar Habash
Proceedings of the 16th Annual conference of the European Association for Machine Translation

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Hebrew Morphological Preprocessing for Statistical Machine Translation
Nimesh Singh | Nizar Habash
Proceedings of the 16th Annual conference of the European Association for Machine Translation

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Can Automatic Post-Editing Make MT More Meaningful
Kristen Parton | Nizar Habash | Kathleen McKeown | Gonzalo Iglesias | Adrià de Gispert
Proceedings of the 16th Annual conference of the European Association for Machine Translation

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Arabic Dialect Processing Tutorial
Mona Diab | Nizar Habash
Tutorial Abstracts at the Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Lost & Found in Translation: Impact of Machine Translated Results on Translingual Information Retrieval
Kristen Parton | Nizar Habash | Kathleen McKeown
Proceedings of the 10th Conference of the Association for Machine Translation in the Americas: Research Papers

In an ideal cross-lingual information retrieval (CLIR) system, a user query would generate a search over documents in a different language and the relevant results would be presented in the user’s language. In practice, CLIR systems are typically evaluated by judging result relevance in the document language, to factor out the effects of translating the results using machine translation (MT). In this paper, we investigate the influence of four different approaches for integrating MT and CLIR on both retrieval accuracy and user judgment of relevancy. We create a corpus with relevance judgments for both human and machine translated results, and use it to quantify the effect that MT quality has on end-to-end relevance. We find that MT errors result in a 16-39% decrease in mean average precision over the ground truth system that uses human translations. MT errors also caused relevant sentences to appear irrelevant – 5-19% of sentences were relevant in human translation, but were judged irrelevant in MT. To counter this degradation, we present two hybrid retrieval models and two automatic MT post-editing techniques and show that these approaches substantially mitigate the errors and improve the end-to-end relevance.

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MT and Arabic Language Issues
Nizar Habash
Proceedings of the 10th Conference of the Association for Machine Translation in the Americas: Tutorials

Arabic poses many interesting challenges to machine translation: ambiguous orthography, rich morphology, complex morpho-syntactic behavior, and numerous dialects. In this tutorial, we introduce the most important themes of challenges and solutions for people working on translation from/to Arabic or any of its dialects. The tutorial is intended for researchers and developers working on MT. The discussion of linguistic issues and how they are addressed in MT will help linguists and professional translators understand the issues machine translation faces when dealing with Arabic and other morphologically rich languages. The tutorial does not expect the attendees to be able to speak/read/write Arabic.

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Identifying Broken Plurals, Irregular Gender, and Rationality in Arabic Text
Sarah Alkuhlani | Nizar Habash
Proceedings of the 13th Conference of the European Chapter of the Association for Computational Linguistics

2011

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Fuzzy Syntactic Reordering for Phrase-based Statistical Machine Translation
Jacob Andreas | Nizar Habash | Owen Rambow
Proceedings of the Sixth Workshop on Statistical Machine Translation

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Filtering Antonymous, Trend-Contrasting, and Polarity-Dissimilar Distributional Paraphrases for Improving Statistical Machine Translation
Yuval Marton | Ahmed El Kholy | Nizar Habash
Proceedings of the Sixth Workshop on Statistical Machine Translation

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Dialectal to Standard Arabic Paraphrasing to Improve Arabic-English Statistical Machine Translation
Wael Salloum | Nizar Habash
Proceedings of the First Workshop on Algorithms and Resources for Modelling of Dialects and Language Varieties

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One-Step Statistical Parsing of Hybrid Dependency-Constituency Syntactic Representations
Kais Dukes | Nizar Habash
Proceedings of the 12th International Conference on Parsing Technologies

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Fast Yet Rich Morphological Analysis
Mohamed Altantawy | Nizar Habash | Owen Rambow
Proceedings of the 9th International Workshop on Finite State Methods and Natural Language Processing

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Automatic Error Analysis for Morphologically Rich Languages
Ahmed El Kholy | Nizar Habash
Proceedings of Machine Translation Summit XIII: Papers

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Using Deep Morphology to Improve Automatic Error Detection in Arabic Handwriting Recognition
Nizar Habash | Ryan Roth
Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies

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Improving Arabic Dependency Parsing with Form-based and Functional Morphological Features
Yuval Marton | Nizar Habash | Owen Rambow
Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies

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A Corpus for Modeling Morpho-Syntactic Agreement in Arabic: Gender, Number and Rationality
Sarah Alkuhlani | Nizar Habash
Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies

2010

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Improving Arabic Dependency Parsing with Lexical and Inflectional Morphological Features
Yuval Marton | Nizar Habash | Owen Rambow
Proceedings of the NAACL HLT 2010 First Workshop on Statistical Parsing of Morphologically-Rich Languages

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Improving Arabic-to-English Statistical Machine Translation by Reordering Post-Verbal Subjects for Alignment
Marine Carpuat | Yuval Marton | Nizar Habash
Proceedings of the ACL 2010 Conference Short Papers

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Machine Translation between Hebrew and Arabic: Needs, Challenges and Preliminary Solutions
Reshef Shilon | Nizar Habash | Alon Lavie | Shuly Wintner
Proceedings of the 9th Conference of the Association for Machine Translation in the Americas: Student Research Workshop

Hebrew and Arabic are related but mutually incomprehensible languages with complex morphology and scarce parallel corpora. Machine translation between the two languages is therefore interesting and challenging. We discuss similarities and differences between Hebrew and Arabic, the benefits and challenges that they induce, respectively, and their implications for machine translation. We highlight the shortcomings of using English as a pivot language and advocate a direct, transfer-based and linguistically-informed (but still statistical, and hence scalable) approach. We report preliminary results of such a system that we are currently developing.

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Morphological Annotation of Quranic Arabic
Kais Dukes | Nizar Habash
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

The Quranic Arabic Corpus (http://corpus.quran.com) is an annotated linguistic resource with multiple layers of annotation including morphological segmentation, part-of-speech tagging, and syntactic analysis using dependency grammar. The motivation behind this work is to produce a resource that enables further analysis of the Quran, the 1,400 year old central religious text of Islam. This paper describes a new approach to morphological annotation of Quranic Arabic, a genre difficult to compare with other forms of Arabic. Processing Quranic Arabic is a unique challenge from a computational point of view, since the vocabulary and spelling differ from Modern Standard Arabic. The Quranic Arabic Corpus differs from other Arabic computational resources in adopting a tagset that closely follows traditional Arabic grammar. We made this decision in order to leverage a large body of existing historical grammatical analysis, and to encourage online collaborative annotation. In this paper, we discuss how the unique challenge of morphological annotation of Quranic Arabic is solved using a multi-stage approach. The different stages include automatic morphological tagging using diacritic edit-distance, two-pass manual verification, and online collaborative annotation. This process is evaluated to validate the appropriateness of the chosen methodology.

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Morphological Analysis and Generation of Arabic Nouns: A Morphemic Functional Approach
Mohamed Altantawy | Nizar Habash | Owen Rambow | Ibrahim Saleh
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

MAGEAD is a morphological analyzer and generator for Modern Standard Arabic (MSA) and its dialects. We introduced MAGEAD in previous work with an implementation of MSA and Levantine Arabic verbs. In this paper, we port that system to MSA nominals (nouns and adjectives), which are far more complex to model than verbs. Our system is a functional morphological analyzer and generator, i.e., it analyzes to and generates from a representation consisting of a lexeme and linguistic feature-value pairs, where the features are syntactically (and perhaps semantically) meaningful, rather than just morphologically. A detailed evaluation of the current implementation comparing it to a commonly used morphological analyzer shows that it has good morphological coverage with precision and recall scores in the 90s. An error analysis reveals that the majority of recall and precision errors are problems in the gold standard or a result of the discrepancy between different models of form-based/functional morphology.

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Orthographic and Morphological Processing for English-Arabic Statistical Machine Translation
Ahmed El Kholy | Nizar Habash
Actes de la 17e conférence sur le Traitement Automatique des Langues Naturelles. Articles longs

Much of the work on Statistical Machine Translation (SMT) from morphologically rich languages has shown that morphological tokenization and orthographic normalization help improve SMT quality because of the sparsity reduction they contribute. In this paper, we study the effect of these processes on SMT when translating into a morphologically rich language, namely Arabic.We explore a space of tokenization schemes and normalization options. We only evaluate on detokenized and orthographically correct (enriched) output. Our results show that the best performing tokenization scheme is that of the Penn Arabic Treebank. Additionally, training on orthographically normalized (reduced) text then jointly enriching and detokenizing the output outperforms training on enriched text.

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Reordering Matrix Post-verbal Subjects for Arabic-to-English SMT
Marine Carpuat | Yuval Marton | Nizar Habash
Actes de la 17e conférence sur le Traitement Automatique des Langues Naturelles. Articles longs

We improve our recently proposed technique for integrating Arabic verb-subject constructions in SMT word alignment (Carpuat et al., 2010) by distinguishing between matrix (or main clause) and non-matrix Arabic verb-subject constructions. In gold translations, most matrix VS (main clause verb-subject) constructions are translated in inverted SV order, while non-matrix (subordinate clause) VS constructions are inverted in only half the cases. In addition, while detecting verbs and their subjects is a hard task, our syntactic parser detects VS constructions better in matrix than in non-matrix clauses. As a result, reordering only matrix VS for word alignment consistently improves translation quality over a phrase-based SMT baseline, and over reordering all VS constructions, in both medium- and large-scale settings. In fact, the improvements obtained by reordering matrix VS on the medium-scale setting remarkably represent 44% of the gain in BLEU and 51% of the gain in TER obtained with a word alignment training bitext that is 5 times larger.

2009

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Automatic Extraction of Lemma-based Bilingual Dictionaries for Morphologically Rich Languages
Ibrahim M. Saleh | Nizar Habash
Proceedings of the Third Workshop on Computational Approaches to Arabic-Script-based Languages (CAASL3)

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CATiB: The Columbia Arabic Treebank
Nizar Habash | Ryan Roth
Proceedings of the ACL-IJCNLP 2009 Conference Short Papers

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Improving the Arabic Pronunciation Dictionary for Phone and Word Recognition with Linguistically-Based Pronunciation Rules
Fadi Biadsy | Nizar Habash | Julia Hirschberg
Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics

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Improving Arabic-Chinese Statistical Machine Translation using English as Pivot Language
Nizar Habash | Jun Hu
Proceedings of the Fourth Workshop on Statistical Machine Translation

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Spoken Arabic Dialect Identification Using Phonotactic Modeling
Fadi Biadsy | Julia Hirschberg | Nizar Habash
Proceedings of the EACL 2009 Workshop on Computational Approaches to Semitic Languages

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Syntactic Reordering for English-Arabic Phrase-Based Machine Translation
Jakob Elming | Nizar Habash
Proceedings of the EACL 2009 Workshop on Computational Approaches to Semitic Languages

2008

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Using Shallow Syntax Information to Improve Word Alignment and Reordering for SMT
Josep M. Crego | Nizar Habash
Proceedings of the Third Workshop on Statistical Machine Translation

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Improving NER in Arabic Using a Morphological Tagger
Benjamin Farber | Dayne Freitag | Nizar Habash | Owen Rambow
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

We discuss a named entity recognition system for Arabic, and show how we incorporated the information provided by MADA, a full morphological tagger which uses a morphological analyzer. Surprisingly, the relevant features used are the capitalization of the English gloss chosen by the tagger, and the fact that an analysis is returned (that a word is not OOV to the morphological analyzer). The use of the tagger also improves over a third system which just uses a morphological analyzer, yielding a 14\% reduction in error over the baseline. We conduct a thorough error analysis to identify sources of success and failure among the variations, and show that by combining the systems in simple ways we can significantly influence the precision-recall trade-off.

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Identification of Naturally Occurring Numerical Expressions in Arabic
Nizar Habash | Ryan Roth
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

In this paper, we define the task of Number Identification in natural context. We present and validate a language-independent semi-automatic approach to quickly building a gold standard for evaluating number identification systems by exploiting hand-aligned parallel data. We also present and extensively evaluate a robust rule-based system for number identification in natural context for Arabic for a variety of number formats and types. The system is shown to have strong performance, achieving, on a blind test, a 94.8% F-score for the task of correctly identifying number expression spans in natural text, and a 92.1% F-score for the task of correctly determining the core numerical value.

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Automatic Learning of Morphological Variations for Handling Out-of-Vocabulary Terms in Urdu-English MT
Nizar Habash | Hayden Metsky
Proceedings of the 8th Conference of the Association for Machine Translation in the Americas: Research Papers

We present an approach for online handling of Out-of-Vocabulary (OOV) terms in Urdu-English MT. Since Urdu is morphologically richer than English, we expect a large portion of the OOV terms to be Urdu morphological variations that are irrelevant to English. We describe an approach to automatically learn English-irrelevant (target-irrelevant) Urdu (source) morphological variation rules from standard phrase tables. These rules are learned in an unsupervised (or lightly supervised) manner by exploiting redundancy in Urdu and collocation with English translations. We use these rules to hypothesize in-vocabulary alternatives to the OOV terms. Our results show that we reduce the OOV rate from a standard baseline average of 2.6% to an average of 0.3% (or 89% relative decrease). We also increase the BLEU score by 0.45 (absolute) and 2.8% (relative) on a standard test set. A manual error analysis shows that 28% of handled OOV cases produce acceptable translations in context.

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Four Techniques for Online Handling of Out-of-Vocabulary Words in Arabic-English Statistical Machine Translation
Nizar Habash
Proceedings of ACL-08: HLT, Short Papers

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Arabic Morphological Tagging, Diacritization, and Lemmatization Using Lexeme Models and Feature Ranking
Ryan Roth | Owen Rambow | Nizar Habash | Mona Diab | Cynthia Rudin
Proceedings of ACL-08: HLT, Short Papers

2007

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Combination of Statistical Word Alignments Based on Multiple Preprocessing Schemes
Jakob Elming | Nizar Habash
Human Language Technologies 2007: The Conference of the North American Chapter of the Association for Computational Linguistics; Companion Volume, Short Papers

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Arabic Diacritization through Full Morphological Tagging
Nizar Habash | Owen Rambow
Human Language Technologies 2007: The Conference of the North American Chapter of the Association for Computational Linguistics; Companion Volume, Short Papers

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Arabic Dialect Processing Tutorial
Mona Diab | Nizar Habash
Proceedings of the Human Language Technology Conference of the NAACL, Companion Volume: Tutorial Abstracts

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Determining Case in Arabic: Learning Complex Linguistic Behavior Requires Complex Linguistic Features
Nizar Habash | Ryan Gabbard | Owen Rambow | Seth Kulick | Mitch Marcus
Proceedings of the 2007 Joint Conference on Empirical Methods in Natural Language Processing and Computational Natural Language Learning (EMNLP-CoNLL)

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Arabic diacritization in the context of statistical machine translation
Mona Diab | Mahmoud Ghoneim | Nizar Habash
Proceedings of Machine Translation Summit XI: Papers

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Syntactic preprocessing for statistical machine translation
Nizar Habash
Proceedings of Machine Translation Summit XI: Papers

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Semi-automatic error analysis for large-scale statistical machine translation
Katrin Kirchhoff | Owen Rambow | Nizar Habash | Mona Diab
Proceedings of Machine Translation Summit XI: Papers

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NLG is still relevant to MT
Nizar Habash
Proceedings of the Workshop on Using corpora for natural language generation

2006

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Combination of Arabic Preprocessing Schemes for Statistical Machine Translation
Fatiha Sadat | Nizar Habash
Proceedings of the 21st International Conference on Computational Linguistics and 44th Annual Meeting of the Association for Computational Linguistics

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MAGEAD: A Morphological Analyzer and Generator for the Arabic Dialects
Nizar Habash | Owen Rambow
Proceedings of the 21st International Conference on Computational Linguistics and 44th Annual Meeting of the Association for Computational Linguistics

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Challenges in Building an Arabic-English GHMT System with SMT Components
Nizar Habash | Bonnie Dorr | Christof Monz
Proceedings of the 7th Conference of the Association for Machine Translation in the Americas: Technical Papers

The research context of this paper is developing hybrid machine translation (MT) systems that exploit the advantages of linguistic rule-based and statistical MT systems. Arabic, as a morphologically rich language, is especially challenging even without addressing the hybridization question. In this paper, we describe the challenges in building an Arabic-English generation-heavy machine translation (GHMT) system and boosting it with statistical machine translation (SMT) components. We present an extensive evaluation of multiple system variants and report positive results on the advantages of hybridization.

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Presentation
Nizar Habash
Proceedings of the 7th Conference of the Association for Machine Translation in the Americas: Panel on hybrid machine translation: why and how?

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Arabic Dialect Processing
Mona Diab | Nizar Habash
Proceedings of the 7th Conference of the Association for Machine Translation in the Americas: Tutorials

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Developing and Using a Pilot Dialectal Arabic Treebank
Mohamed Maamouri | Ann Bies | Tim Buckwalter | Mona Diab | Nizar Habash | Owen Rambow | Dalila Tabessi
Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC’06)

In this paper, we describe the methodological procedures and issues that emerged from the development of a pilot Levantine Arabic Treebank (LATB) at the Linguistic Data Consortium (LDC) and its use at the Johns Hopkins University (JHU) Center for Language and Speech Processing workshop on Parsing Arabic Dialects (PAD). This pilot, consisting of morphological and syntactic annotation of approximately 26,000 words of Levantine Arabic conversational telephone speech, was developed under severe time constraints; hence the LDC team drew on their experience in treebanking Modern Standard Arabic (MSA) text. The resulting Levantine dialect treebanked corpus was used by the PAD team to develop and evaluate parsers for Levantine dialect texts. The parsers were trained on MSA resources and adapted using dialect-MSA lexical resources (some developed especially for this task) and existing linguistic knowledge about syntactic differences between MSA and dialect. The use of the LATB for development and evaluation of syntactic parsers allowed the PAD team to provide feedbasck to the LDC treebank developers. In this paper, we describe the creation of resources for this corpus, as well as transformations on the corpus to eliminate speech effects and lessen the gap between our pre-existing MSA resources and the new dialectal corpus

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Inter-annotator Agreement on a Multilingual Semantic Annotation Task
Rebecca Passonneau | Nizar Habash | Owen Rambow
Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC’06)

Six sites participated in the Interlingual Annotation of Multilingual Text Corpora (IAMTC) project (Dorr et al., 2004; Farwell et al., 2004; Mitamura et al., 2004). Parsed versions of English translations of news articles in Arabic, French, Hindi, Japanese, Korean and Spanish were annotated by up to ten annotators. Their task was to match open-class lexical items (nouns, verbs, adjectives, adverbs) to one or more concepts taken from the Omega ontology (Philpot et al., 2003), and to identify theta roles for verb arguments. The annotated corpus is intended to be a resource for meaning-based approaches to machine translation. Here we discuss inter-annotator agreement for the corpus. The annotation task is characterized by annotators’ freedom to select multiple concepts or roles per lexical item. As a result, the annotation categories are sets, the number of which is bounded only by the number of distinct annotator-lexical item pairs. We use a reliability metric designed to handle partial agreement between sets. The best results pertain to the part of the ontology derived from WordNet. We examine change over the course of the project, differences among annotators, and differences across parts of speech. Our results suggest a strong learning effect early in the project.

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Parallel Syntactic Annotation of Multiple Languages
Owen Rambow | Bonnie Dorr | David Farwell | Rebecca Green | Nizar Habash | Stephen Helmreich | Eduard Hovy | Lori Levin | Keith J. Miller | Teruko Mitamura | Florence Reeder | Advaith Siddharthan
Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC’06)

This paper describes an effort to investigate the incrementally deepening development of an interlingua notation, validated by human annotation of texts in English plus six languages. We begin with deep syntactic annotation, and in this paper present a series of annotation manuals for six different languages at the deep-syntactic level of representation. Many syntactic differences between languages are removed in the proposed syntactic annotation, making them useful resources for multilingual NLP projects with semantic components.

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Design, Construction and Validation of an Arabic-English Conceptual Interlingua for Cross-lingual Information Retrieval
Nizar Habash | Clinton Mah | Sabiha Imran | Randy Calistri-Yeh | Páraic Sheridan
Proceedings of the Fifth International Conference on Language Resources and Evaluation (LREC’06)

This paper describes the issues involved in extending a trans-lingual lexicon, the TextWise Conceptual Interlingua (CI), with Arabic terms. The Conceptual Interlingua is based on the Princeton English WordNet (Fellbaum, 1998). It is a central component in the cross-lingual information retrieval (CLIR) system CINDOR (Conceptual INterlingua for DOcument Retrieval). Arabic has a rich morphological system combining templatic and affixational paradigms for both inflectional and derivational morphology. This rich morphology poses a major challenge to the design and building of the Arabic CI and also its validation. This is because the available resources for Arabic, whether manually constructed bilingual lexicons or lexicons automatically derived from bilingual parallel corpora, exist at different levels of morphological representation. We describe here the issues and decisions made in the design and construction of the Arabic-English CI using different types of manual and automatic resources. We also present the results of an extensive validation of the Arabic CI and briefly discuss the evaluation of its use for CLIR on the TREC Arabic Benchmark collection.

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Arabic Preprocessing Schemes for Statistical Machine Translation
Nizar Habash | Fatiha Sadat
Proceedings of the Human Language Technology Conference of the NAACL, Companion Volume: Short Papers

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Parsing Arabic Dialects
David Chiang | Mona Diab | Nizar Habash | Owen Rambow | Safiullah Shareef
11th Conference of the European Chapter of the Association for Computational Linguistics

2005

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Proceedings of the ACL Workshop on Computational Approaches to Semitic Languages
Kareem Darwish | Mona Diab | Nizar Habash
Proceedings of the ACL Workshop on Computational Approaches to Semitic Languages

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Morphological Analysis and Generation for Arabic Dialects
Nizar Habash | Owen Rambow | George Kiraz
Proceedings of the ACL Workshop on Computational Approaches to Semitic Languages

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Arabic Tokenization, Part-of-Speech Tagging and Morphological Disambiguation in One Fell Swoop
Nizar Habash | Owen Rambow
Proceedings of the 43rd Annual Meeting of the Association for Computational Linguistics (ACL’05)

2004

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Interlingual Annotation of Multilingual Text Corpora
Stephen Helmreich | David Farwell | Bonnie Dorr | Nizar Habash | Lori Levin | Teruko Mitamura | Florence Reeder | Keith Miller | Eduard Hovy | Owen Rambow | Advaith Siddharthan
Proceedings of the Workshop Frontiers in Corpus Annotation at HLT-NAACL 2004

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Multi-Align: combining linguistic and statistical techniques to improve alignments for adaptable MT
Necip Fazil Ayan | Bonnie Dorr | Nizar Habash
Proceedings of the 6th Conference of the Association for Machine Translation in the Americas: Technical Papers

An adaptable statistical or hybrid MT system relies heavily on the quality of word-level alignments of real-world data. Statistical alignment approaches provide a reasonable initial estimate for word alignment. However, they cannot handle certain types of linguistic phenomena such as long-distance dependencies and structural differences between languages. We address this issue in Multi-Align, a new framework for incremental testing of different alignment algorithms and their combinations. Our design allows users to tune their systems to the properties of a particular genre/domain while still benefiting from general linguistic knowledge associated with a language pair. We demonstrate that a combination of statistical and linguistically-informed alignments can resolve translation divergences during the alignment process.

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Interlingual annotation for MT development
Florence Reeder | Bonnie Dorr | David Farwell | Nizar Habash | Stephen Helmreich | Eduard Hovy | Lori Levin | Teruko Mitamura | Keith Miller | Owen Rambow | Advaith Siddharthan
Proceedings of the 6th Conference of the Association for Machine Translation in the Americas: Technical Papers

MT systems that use only superficial representations, including the current generation of statistical MT systems, have been successful and useful. However, they will experience a plateau in quality, much like other “silver bullet” approaches to MT. We pursue work on the development of interlingual representations for use in symbolic or hybrid MT systems. In this paper, we describe the creation of an interlingua and the development of a corpus of semantically annotated text, to be validated in six languages and evaluated in several ways. We have established a distributed, well-functioning research methodology, designed a preliminary interlingua notation, created annotation manuals and tools, developed a test collection in six languages with associated English translations, annotated some 150 translations, and designed and applied various annotation metrics. We describe the data sets being annotated and the interlingual (IL) representation language which uses two ontologies and a systematic theta-role list. We present the annotation tools built and outline the annotation process. Following this, we describe our evaluation methodology and conclude with a summary of issues that have arisen.

2003

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Matador: a large-scale Spanish-English GHMT system
Nizar Habash
Proceedings of Machine Translation Summit IX: Papers

This paper describes and evaluates Matador, an implemented large-scale Spanish-English MT system built in the Generation-Heavy Hybrid Machine Translation (GHMT) approach. An extensive evaluation shows that Matador has a higher degree of robustness and superior output quality, in terms of grammaticality and accuracy, when compared to a primarily statistical approach.

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Matador: Spanish-English GHMT
Nizar Habash
Proceedings of Machine Translation Summit IX: System Presentations

This paper presents the online demo of Matador, a large-scale Spanish-English machine translation system implemented following the Generation-heavy Hybrid Machine Translation (GHMT) approach.

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CatVar: a database of categorial variations for English
Nizar Habash | Bonnie Dorr
Proceedings of Machine Translation Summit IX: System Presentations

We present a new large-scale database called “CatVar” (Habash and Dorr, 2003) which contains categorial variations of English lexemes. Due to the prevalence of cross-language categorial variation in multilingual applications, our categorial-variation resource may serve as an integral part of a diverse range of natural language applications. Thus, the research reported herein overlaps heavily with that of the machine-translation, lexicon-construction, and information-retrieval communities. We demonstrate this database, embedded in a graphical interface; we also show a GUI for user input of corrections to the database.

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Semitic linguistic phenomena and variations
Nizar Habash
Workshop on Machine Translation for Semitic languages: issues and approaches

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A Categorial Variation Database for English
Nizar Habash | Bonnie Dorr
Proceedings of the 2003 Human Language Technology Conference of the North American Chapter of the Association for Computational Linguistics

2002

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Generation-Heavy Hybrid Machine Translation
Nizar Habash
Proceedings of the International Natural Language Generation Conference

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DUSTer: a method for unraveling cross-language divergences for statistical word-level alignment
Bonnie Dorr | Lisa Pearl | Rebecca Hwa | Nizar Habash
Proceedings of the 5th Conference of the Association for Machine Translation in the Americas: Technical Papers

The frequent occurrence of divergenceS—structural differences between languages—presents a great challenge for statistical word-level alignment. In this paper, we introduce DUSTer, a method for systematically identifying common divergence types and transforming an English sentence structure to bear a closer resemblance to that of another language. Our ultimate goal is to enable more accurate alignment and projection of dependency trees in another language without requiring any training on dependency-tree data in that language. We present an empirical analysis comparing the complexities of performing word-level alignments with and without divergence handling. Our results suggest that our approach facilitates word-level alignment, particularly for sentence pairs containing divergences.

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Handling translation divergences: combining statistical and symbolic techniques in generation-heavy machine translation
Nizar Habash | Bonnie Dorr
Proceedings of the 5th Conference of the Association for Machine Translation in the Americas: Technical Papers

This paper describes a novel approach to handling translation divergences in a Generation-Heavy Hybrid Machine Translation (GHMT) system. The translation divergence problem is usually reserved for Transfer and Interlingual MT because it requires a large combination of complex lexical and structural mappings. A major requirement of these approaches is the accessibility of large amounts of explicit symmetric knowledge for both source and target languages. This limitation renders Transfer and Interlingual approaches ineffective in the face of structurally-divergent language pairs with asymmetric resources. GHMT addresses the more common form of this problem, source-poor/targetrich, by fully exploiting symbolic and statistical target-language resources. This non-interlingual non-transfer approach is accomplished by using target-language lexical semantics, categorial variations and subcategorization frames to overgenerate multiple lexico-structural variations from a target-glossed syntactic dependency of the source-language sentence. The symbolic overgeneration, which accounts for different possible translation divergences, is constrained by a statistical target-language model.

2001

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Large scale language independent generation using thematic hierarchies
Nizar Habash | Bonnie Dorr
Proceedings of Machine Translation Summit VIII

2000

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Oxygen: a language independent linearization engine
Nizar Habash
Proceedings of the Fourth Conference of the Association for Machine Translation in the Americas: Technical Papers

This paper describes a language independent linearization engine, oxyGen. This system compiles target language grammars into programs that take feature graphs as inputs and generate word lattices that can be passed along to the statistical extraction module of the generation system Nitrogen. The grammars are written using a flexible and powerful language, oxyL, that has the power of a programming language but focuses on natural language realization. This engine has been used successfully in creating an English linearization program that is currently employed as part of a Chinese-English machine translation system.

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Generation from Lexical Conceptual Structures
David Traum | Nizar Habash
NAACL-ANLP 2000 Workshop: Applied Interlinguas: Practical Applications of Interlingual Approaches to NLP

1998

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A thematic hierarchy for efficient generation from lexical-conceptual structure
Bonnie Dorr | Nizar Habash | David Traum
Proceedings of the Third Conference of the Association for Machine Translation in the Americas: Technical Papers

This paper describes an implemented algorithm for syntactic realization of a target-language sentence from an interlingual representation called Lexical Conceptual Structure (LCS). We provide a mapping between LCS thematic roles and Abstract Meaning Representation (AMR) relations; these relations serve as input to an off-the-shelf generator (Nitrogen). There are two contributions of this work: (1) the development of a thematic hierarchy that provides ordering information for realization of arguments in their surface positions; (2) the provision of a diagnostic tool for detecting inconsistencies in an existing online LCS-based lexicon that allows us to enhance principles for thematic-role assignment.
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