Shervin Malmasi

Also published as: Shevin Malmasi


2022

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Proceedings of The Fifth Workshop on e-Commerce and NLP (ECNLP 5)
Shervin Malmasi | Oleg Rokhlenko | Nicola Ueffing | Ido Guy | Eugene Agichtein | Surya Kallumadi
Proceedings of The Fifth Workshop on e-Commerce and NLP (ECNLP 5)

2021

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Proceedings of the Third Workshop on Privacy in Natural Language Processing
Oluwaseyi Feyisetan | Sepideh Ghanavati | Shervin Malmasi | Patricia Thaine
Proceedings of the Third Workshop on Privacy in Natural Language Processing

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Proceedings of The 4th Workshop on e-Commerce and NLP
Shervin Malmasi | Surya Kallumadi | Nicola Ueffing | Oleg Rokhlenko | Eugene Agichtein | Ido Guy
Proceedings of The 4th Workshop on e-Commerce and NLP

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GEMNET: Effective Gated Gazetteer Representations for Recognizing Complex Entities in Low-context Input
Tao Meng | Anjie Fang | Oleg Rokhlenko | Shervin Malmasi
Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

Named Entity Recognition (NER) remains difficult in real-world settings; current challenges include short texts (low context), emerging entities, and complex entities (e.g. movie names). Gazetteer features can help, but results have been mixed due to challenges with adding extra features, and a lack of realistic evaluation data. It has been shown that including gazetteer features can cause models to overuse or underuse them, leading to poor generalization. We propose GEMNET, a novel approach for gazetteer knowledge integration, including (1) a flexible Contextual Gazetteer Representation (CGR) encoder that can be fused with any word-level model; and (2) a Mixture-of- Experts gating network that overcomes the feature overuse issue by learning to conditionally combine the context and gazetteer features, instead of assigning them fixed weights. To comprehensively evaluate our approaches, we create 3 large NER datasets (24M tokens) reflecting current challenges. In an uncased setting, our methods show large gains (up to +49% F1) in recognizing difficult entities compared to existing baselines. On standard benchmarks, we achieve a new uncased SOTA on CoNLL03 and WNUT17.

2020

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Proceedings of the Second Workshop on Privacy in NLP
Oluwaseyi Feyisetan | Sepideh Ghanavati | Shervin Malmasi | Patricia Thaine
Proceedings of the Second Workshop on Privacy in NLP

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Proceedings of the Second Workshop on Trolling, Aggression and Cyberbullying
Ritesh Kumar | Atul Kr. Ojha | Bornini Lahiri | Marcos Zampieri | Shervin Malmasi | Vanessa Murdock | Daniel Kadar
Proceedings of the Second Workshop on Trolling, Aggression and Cyberbullying

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Evaluating Aggression Identification in Social Media
Ritesh Kumar | Atul Kr. Ojha | Shervin Malmasi | Marcos Zampieri
Proceedings of the Second Workshop on Trolling, Aggression and Cyberbullying

In this paper, we present the report and findings of the Shared Task on Aggression and Gendered Aggression Identification organised as part of the Second Workshop on Trolling, Aggression and Cyberbullying (TRAC - 2) at LREC 2020. The task consisted of two sub-tasks - aggression identification (sub-task A) and gendered identification (sub-task B) - in three languages - Bangla, Hindi and English. For this task, the participants were provided with a dataset of approximately 5,000 instances from YouTube comments in each language. For testing, approximately 1,000 instances were provided in each language for each sub-task. A total of 70 teams registered to participate in the task and 19 teams submitted their test runs. The best system obtained a weighted F-score of approximately 0.80 in sub-task A for all the three languages. While approximately 0.87 in sub-task B for all the three languages.

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Proceedings of The 3rd Workshop on e-Commerce and NLP
Shervin Malmasi | Surya Kallumadi | Nicola Ueffing | Oleg Rokhlenko | Eugene Agichtein | Ido Guy
Proceedings of The 3rd Workshop on e-Commerce and NLP

2019

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SemEval-2019 Task 6: Identifying and Categorizing Offensive Language in Social Media (OffensEval)
Marcos Zampieri | Shervin Malmasi | Preslav Nakov | Sara Rosenthal | Noura Farra | Ritesh Kumar
Proceedings of the 13th International Workshop on Semantic Evaluation

We present the results and the main findings of SemEval-2019 Task 6 on Identifying and Categorizing Offensive Language in Social Media (OffensEval). The task was based on a new dataset, the Offensive Language Identification Dataset (OLID), which contains over 14,000 English tweets, and it featured three sub-tasks. In sub-task A, systems were asked to discriminate between offensive and non-offensive posts. In sub-task B, systems had to identify the type of offensive content in the post. Finally, in sub-task C, systems had to detect the target of the offensive posts. OffensEval attracted a large number of participants and it was one of the most popular tasks in SemEval-2019. In total, nearly 800 teams signed up to participate in the task and 115 of them submitted results, which are presented and analyzed in this report.

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UTFPR at SemEval-2019 Task 5: Hate Speech Identification with Recurrent Neural Networks
Gustavo Henrique Paetzold | Marcos Zampieri | Shervin Malmasi
Proceedings of the 13th International Workshop on Semantic Evaluation

In this paper we revisit the problem of automatically identifying hate speech in posts from social media. We approach the task using a system based on minimalistic compositional Recurrent Neural Networks (RNN). We tested our approach on the SemEval-2019 Task 5: Multilingual Detection of Hate Speech Against Immigrants and Women in Twitter (HatEval) shared task dataset. The dataset made available by the HatEval organizers contained English and Spanish posts retrieved from Twitter annotated with respect to the presence of hateful content and its target. In this paper we present the results obtained by our system in comparison to the other entries in the shared task. Our system achieved competitive performance ranking 7th in sub-task A out of 62 systems in the English track.

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Proceedings of the Sixth Workshop on NLP for Similar Languages, Varieties and Dialects
Marcos Zampieri | Preslav Nakov | Shervin Malmasi | Nikola Ljubešić | Jörg Tiedemann | Ahmed Ali
Proceedings of the Sixth Workshop on NLP for Similar Languages, Varieties and Dialects

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A Report on the Third VarDial Evaluation Campaign
Marcos Zampieri | Shervin Malmasi | Yves Scherrer | Tanja Samardžić | Francis Tyers | Miikka Silfverberg | Natalia Klyueva | Tung-Le Pan | Chu-Ren Huang | Radu Tudor Ionescu | Andrei M. Butnaru | Tommi Jauhiainen
Proceedings of the Sixth Workshop on NLP for Similar Languages, Varieties and Dialects

In this paper, we present the findings of the Third VarDial Evaluation Campaign organized as part of the sixth edition of the workshop on Natural Language Processing (NLP) for Similar Languages, Varieties and Dialects (VarDial), co-located with NAACL 2019. This year, the campaign included five shared tasks, including one task re-run – German Dialect Identification (GDI) – and four new tasks – Cross-lingual Morphological Analysis (CMA), Discriminating between Mainland and Taiwan variation of Mandarin Chinese (DMT), Moldavian vs. Romanian Cross-dialect Topic identification (MRC), and Cuneiform Language Identification (CLI). A total of 22 teams submitted runs across the five shared tasks. After the end of the competition, we received 14 system description papers, which are published in the VarDial workshop proceedings and referred to in this report.

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Findings of the 2019 Conference on Machine Translation (WMT19)
Loïc Barrault | Ondřej Bojar | Marta R. Costa-jussà | Christian Federmann | Mark Fishel | Yvette Graham | Barry Haddow | Matthias Huck | Philipp Koehn | Shervin Malmasi | Christof Monz | Mathias Müller | Santanu Pal | Matt Post | Marcos Zampieri
Proceedings of the Fourth Conference on Machine Translation (Volume 2: Shared Task Papers, Day 1)

This paper presents the results of the premier shared task organized alongside the Conference on Machine Translation (WMT) 2019. Participants were asked to build machine translation systems for any of 18 language pairs, to be evaluated on a test set of news stories. The main metric for this task is human judgment of translation quality. The task was also opened up to additional test suites to probe specific aspects of translation.

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Predicting the Type and Target of Offensive Posts in Social Media
Marcos Zampieri | Shervin Malmasi | Preslav Nakov | Sara Rosenthal | Noura Farra | Ritesh Kumar
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)

As offensive content has become pervasive in social media, there has been much research in identifying potentially offensive messages. However, previous work on this topic did not consider the problem as a whole, but rather focused on detecting very specific types of offensive content, e.g., hate speech, cyberbulling, or cyber-aggression. In contrast, here we target several different kinds of offensive content. In particular, we model the task hierarchically, identifying the type and the target of offensive messages in social media. For this purpose, we complied the Offensive Language Identification Dataset (OLID), a new dataset with tweets annotated for offensive content using a fine-grained three-layer annotation scheme, which we make publicly available. We discuss the main similarities and differences between OLID and pre-existing datasets for hate speech identification, aggression detection, and similar tasks. We further experiment with and we compare the performance of different machine learning models on OLID.

2018

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Classifying Patent Applications with Ensemble Methods
Fernando Benites | Shervin Malmasi | Marcos Zampieri
Proceedings of the Australasian Language Technology Association Workshop 2018

We present methods for the automatic classification of patent applications using an annotated dataset provided by the organizers of the ALTA 2018 shared task - Classifying Patent Applications. The goal of the task is to use computational methods to categorize patent applications according to a coarse-grained taxonomy of eight classes based on the International Patent Classification (IPC). We tested a variety of approaches for this task and the best results, 0.778 micro-averaged F1-Score, were achieved by SVM ensembles using a combination of words and characters as features. Our team, BMZ, was ranked first among 14 teams in the competition.

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Native Language Identification With Classifier Stacking and Ensembles
Shervin Malmasi | Mark Dras
Computational Linguistics, Volume 44, Issue 3 - September 2018

Ensemble methods using multiple classifiers have proven to be among the most successful approaches for the task of Native Language Identification (NLI), achieving the current state of the art. However, a systematic examination of ensemble methods for NLI has yet to be conducted. Additionally, deeper ensemble architectures such as classifier stacking have not been closely evaluated. We present a set of experiments using three ensemble-based models, testing each with multiple configurations and algorithms. This includes a rigorous application of meta-classification models for NLI, achieving state-of-the-art results on several large data sets, evaluated in both intra-corpus and cross-corpus modes.

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A Report on the Complex Word Identification Shared Task 2018
Seid Muhie Yimam | Chris Biemann | Shervin Malmasi | Gustavo Paetzold | Lucia Specia | Sanja Štajner | Anaïs Tack | Marcos Zampieri
Proceedings of the Thirteenth Workshop on Innovative Use of NLP for Building Educational Applications

We report the findings of the second Complex Word Identification (CWI) shared task organized as part of the BEA workshop co-located with NAACL-HLT’2018. The second CWI shared task featured multilingual and multi-genre datasets divided into four tracks: English monolingual, German monolingual, Spanish monolingual, and a multilingual track with a French test set, and two tasks: binary classification and probabilistic classification. A total of 12 teams submitted their results in different task/track combinations and 11 of them wrote system description papers that are referred to in this report and appear in the BEA workshop proceedings.

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A Portuguese Native Language Identification Dataset
Iria del Río Gayo | Marcos Zampieri | Shervin Malmasi
Proceedings of the Thirteenth Workshop on Innovative Use of NLP for Building Educational Applications

In this paper we present NLI-PT, the first Portuguese dataset compiled for Native Language Identification (NLI), the task of identifying an author’s first language based on their second language writing. The dataset includes 1,868 student essays written by learners of European Portuguese, native speakers of the following L1s: Chinese, English, Spanish, German, Russian, French, Japanese, Italian, Dutch, Tetum, Arabic, Polish, Korean, Romanian, and Swedish. NLI-PT includes the original student text and four different types of annotation: POS, fine-grained POS, constituency parses, and dependency parses. NLI-PT can be used not only in NLI but also in research on several topics in the field of Second Language Acquisition and educational NLP. We discuss possible applications of this dataset and present the results obtained for the first lexical baseline system for Portuguese NLI.

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Proceedings of the Fifth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial 2018)
Marcos Zampieri | Preslav Nakov | Nikola Ljubešić | Jörg Tiedemann | Shervin Malmasi | Ahmed Ali
Proceedings of the Fifth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial 2018)

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Language Identification and Morphosyntactic Tagging: The Second VarDial Evaluation Campaign
Marcos Zampieri | Shervin Malmasi | Preslav Nakov | Ahmed Ali | Suwon Shon | James Glass | Yves Scherrer | Tanja Samardžić | Nikola Ljubešić | Jörg Tiedemann | Chris van der Lee | Stefan Grondelaers | Nelleke Oostdijk | Dirk Speelman | Antal van den Bosch | Ritesh Kumar | Bornini Lahiri | Mayank Jain
Proceedings of the Fifth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial 2018)

We present the results and the findings of the Second VarDial Evaluation Campaign on Natural Language Processing (NLP) for Similar Languages, Varieties and Dialects. The campaign was organized as part of the fifth edition of the VarDial workshop, collocated with COLING’2018. This year, the campaign included five shared tasks, including two task re-runs – Arabic Dialect Identification (ADI) and German Dialect Identification (GDI) –, and three new tasks – Morphosyntactic Tagging of Tweets (MTT), Discriminating between Dutch and Flemish in Subtitles (DFS), and Indo-Aryan Language Identification (ILI). A total of 24 teams submitted runs across the five shared tasks, and contributed 22 system description papers, which were included in the VarDial workshop proceedings and are referred to in this report.

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Discriminating between Indo-Aryan Languages Using SVM Ensembles
Alina Maria Ciobanu | Marcos Zampieri | Shervin Malmasi | Santanu Pal | Liviu P. Dinu
Proceedings of the Fifth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial 2018)

In this paper we present a system based on SVM ensembles trained on characters and words to discriminate between five similar languages of the Indo-Aryan family: Hindi, Braj Bhasha, Awadhi, Bhojpuri, and Magahi. The system competed in the Indo-Aryan Language Identification (ILI) shared task organized within the VarDial Evaluation Campaign 2018. Our best entry in the competition, named ILIdentification, scored 88.95% F1 score and it was ranked 3rd out of 8 teams.

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German Dialect Identification Using Classifier Ensembles
Alina Maria Ciobanu | Shervin Malmasi | Liviu P. Dinu
Proceedings of the Fifth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial 2018)

In this paper we present the GDI classification entry to the second German Dialect Identification (GDI) shared task organized within the scope of the VarDial Evaluation Campaign 2018. We present a system based on SVM classifier ensembles trained on characters and words. The system was trained on a collection of speech transcripts of five Swiss-German dialects provided by the organizers. The transcripts included in the dataset contained speakers from Basel, Bern, Lucerne, and Zurich. Our entry in the challenge reached 62.03% F1 score and was ranked third out of eight teams.

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Proceedings of the First Workshop on Trolling, Aggression and Cyberbullying (TRAC-2018)
Ritesh Kumar | Atul Kr. Ojha | Marcos Zampieri | Shervin Malmasi
Proceedings of the First Workshop on Trolling, Aggression and Cyberbullying (TRAC-2018)

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Benchmarking Aggression Identification in Social Media
Ritesh Kumar | Atul Kr. Ojha | Shervin Malmasi | Marcos Zampieri
Proceedings of the First Workshop on Trolling, Aggression and Cyberbullying (TRAC-2018)

In this paper, we present the report and findings of the Shared Task on Aggression Identification organised as part of the First Workshop on Trolling, Aggression and Cyberbullying (TRAC - 1) at COLING 2018. The task was to develop a classifier that could discriminate between Overtly Aggressive, Covertly Aggressive, and Non-aggressive texts. For this task, the participants were provided with a dataset of 15,000 aggression-annotated Facebook Posts and Comments each in Hindi (in both Roman and Devanagari script) and English for training and validation. For testing, two different sets - one from Facebook and another from a different social media - were provided. A total of 130 teams registered to participate in the task, 30 teams submitted their test runs, and finally 20 teams also sent their system description paper which are included in the TRAC workshop proceedings. The best system obtained a weighted F-score of 0.64 for both Hindi and English on the Facebook test sets, while the best scores on the surprise set were 0.60 and 0.50 for English and Hindi respectively. The results presented in this report depict how challenging the task is. The positive response from the community and the great levels of participation in the first edition of this shared task also highlights the interest in this topic.

2017

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Detecting Hate Speech in Social Media
Shervin Malmasi | Marcos Zampieri
Proceedings of the International Conference Recent Advances in Natural Language Processing, RANLP 2017

In this paper we examine methods to detect hate speech in social media, while distinguishing this from general profanity. We aim to establish lexical baselines for this task by applying supervised classification methods using a recently released dataset annotated for this purpose. As features, our system uses character n-grams, word n-grams and word skip-grams. We obtain results of 78% accuracy in identifying posts across three classes. Results demonstrate that the main challenge lies in discriminating profanity and hate speech from each other. A number of directions for future work are discussed.

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Proceedings of the Fourth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial)
Preslav Nakov | Marcos Zampieri | Nikola Ljubešić | Jörg Tiedemann | Shevin Malmasi | Ahmed Ali
Proceedings of the Fourth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial)

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Findings of the VarDial Evaluation Campaign 2017
Marcos Zampieri | Shervin Malmasi | Nikola Ljubešić | Preslav Nakov | Ahmed Ali | Jörg Tiedemann | Yves Scherrer | Noëmi Aepli
Proceedings of the Fourth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial)

We present the results of the VarDial Evaluation Campaign on Natural Language Processing (NLP) for Similar Languages, Varieties and Dialects, which we organized as part of the fourth edition of the VarDial workshop at EACL’2017. This year, we included four shared tasks: Discriminating between Similar Languages (DSL), Arabic Dialect Identification (ADI), German Dialect Identification (GDI), and Cross-lingual Dependency Parsing (CLP). A total of 19 teams submitted runs across the four tasks, and 15 of them wrote system description papers.

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German Dialect Identification in Interview Transcriptions
Shervin Malmasi | Marcos Zampieri
Proceedings of the Fourth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial)

This paper presents three systems submitted to the German Dialect Identification (GDI) task at the VarDial Evaluation Campaign 2017. The task consists of training models to identify the dialect of Swiss-German speech transcripts. The dialects included in the GDI dataset are Basel, Bern, Lucerne, and Zurich. The three systems we submitted are based on: a plurality ensemble, a mean probability ensemble, and a meta-classifier trained on character and word n-grams. The best results were obtained by the meta-classifier achieving 68.1% accuracy and 66.2% F1-score, ranking first among the 10 teams which participated in the GDI shared task.

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Arabic Dialect Identification Using iVectors and ASR Transcripts
Shervin Malmasi | Marcos Zampieri
Proceedings of the Fourth Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial)

This paper presents the systems submitted by the MAZA team to the Arabic Dialect Identification (ADI) shared task at the VarDial Evaluation Campaign 2017. The goal of the task is to evaluate computational models to identify the dialect of Arabic utterances using both audio and text transcriptions. The ADI shared task dataset included Modern Standard Arabic (MSA) and four Arabic dialects: Egyptian, Gulf, Levantine, and North-African. The three systems submitted by MAZA are based on combinations of multiple machine learning classifiers arranged as (1) voting ensemble; (2) mean probability ensemble; (3) meta-classifier. The best results were obtained by the meta-classifier achieving 71.7% accuracy, ranking second among the six teams which participated in the ADI shared task.

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A Report on the 2017 Native Language Identification Shared Task
Shervin Malmasi | Keelan Evanini | Aoife Cahill | Joel Tetreault | Robert Pugh | Christopher Hamill | Diane Napolitano | Yao Qian
Proceedings of the 12th Workshop on Innovative Use of NLP for Building Educational Applications

Native Language Identification (NLI) is the task of automatically identifying the native language (L1) of an individual based on their language production in a learned language. It is typically framed as a classification task where the set of L1s is known a priori. Two previous shared tasks on NLI have been organized where the aim was to identify the L1 of learners of English based on essays (2013) and spoken responses (2016) they provided during a standardized assessment of academic English proficiency. The 2017 shared task combines the inputs from the two prior tasks for the first time. There are three tracks: NLI on the essay only, NLI on the spoken response only (based on a transcription of the response and i-vector acoustic features), and NLI using both responses. We believe this makes for a more interesting shared task while building on the methods and results from the previous two shared tasks. In this paper, we report the results of the shared task. A total of 19 teams competed across the three different sub-tasks. The fusion track showed that combining the written and spoken responses provides a large boost in prediction accuracy. Multiple classifier systems (e.g. ensembles and meta-classifiers) were the most effective in all tasks, with most based on traditional classifiers (e.g. SVMs) with lexical/syntactic features.

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Complex Word Identification: Challenges in Data Annotation and System Performance
Marcos Zampieri | Shervin Malmasi | Gustavo Paetzold | Lucia Specia
Proceedings of the 4th Workshop on Natural Language Processing Techniques for Educational Applications (NLPTEA 2017)

This paper revisits the problem of complex word identification (CWI) following up the SemEval CWI shared task. We use ensemble classifiers to investigate how well computational methods can discriminate between complex and non-complex words. Furthermore, we analyze the classification performance to understand what makes lexical complexity challenging. Our findings show that most systems performed poorly on the SemEval CWI dataset, and one of the reasons for that is the way in which human annotation was performed.

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Unsupervised Text Segmentation Based on Native Language Characteristics
Shervin Malmasi | Mark Dras | Mark Johnson | Lan Du | Magdalena Wolska
Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Most work on segmenting text does so on the basis of topic changes, but it can be of interest to segment by other, stylistically expressed characteristics such as change of authorship or native language. We propose a Bayesian unsupervised text segmentation approach to the latter. While baseline models achieve essentially random segmentation on our task, indicating its difficulty, a Bayesian model that incorporates appropriately compact language models and alternating asymmetric priors can achieve scores on the standard metrics around halfway to perfect segmentation.

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Feature Hashing for Language and Dialect Identification
Shervin Malmasi | Mark Dras
Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

We evaluate feature hashing for language identification (LID), a method not previously used for this task. Using a standard dataset, we first show that while feature performance is high, LID data is highly dimensional and mostly sparse (>99.5%) as it includes large vocabularies for many languages; memory requirements grow as languages are added. Next we apply hashing using various hash sizes, demonstrating that there is no performance loss with dimensionality reductions of up to 86%. We also show that using an ensemble of low-dimension hash-based classifiers further boosts performance. Feature hashing is highly useful for LID and holds great promise for future work in this area.

2016

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Predicting Post Severity in Mental Health Forums
Shervin Malmasi | Marcos Zampieri | Mark Dras
Proceedings of the Third Workshop on Computational Linguistics and Clinical Psychology

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Proceedings of the Third Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial3)
Preslav Nakov | Marcos Zampieri | Liling Tan | Nikola Ljubešić | Jörg Tiedemann | Shervin Malmasi
Proceedings of the Third Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial3)

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Discriminating between Similar Languages and Arabic Dialect Identification: A Report on the Third DSL Shared Task
Shervin Malmasi | Marcos Zampieri | Nikola Ljubešić | Preslav Nakov | Ahmed Ali | Jörg Tiedemann
Proceedings of the Third Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial3)

We present the results of the third edition of the Discriminating between Similar Languages (DSL) shared task, which was organized as part of the VarDial’2016 workshop at COLING’2016. The challenge offered two subtasks: subtask 1 focused on the identification of very similar languages and language varieties in newswire texts, whereas subtask 2 dealt with Arabic dialect identification in speech transcripts. A total of 37 teams registered to participate in the task, 24 teams submitted test results, and 20 teams also wrote system description papers. High-order character n-grams were the most successful feature, and the best classification approaches included traditional supervised learning methods such as SVM, logistic regression, and language models, while deep learning approaches did not perform very well.

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Subdialectal Differences in Sorani Kurdish
Shervin Malmasi
Proceedings of the Third Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial3)

In this study we apply classification methods for detecting subdialectal differences in Sorani Kurdish texts produced in different regions, namely Iran and Iraq. As Sorani is a low-resource language, no corpus including texts from different regions was readily available. To this end, we identified data sources that could be leveraged for this task to create a dataset of 200,000 sentences. Using surface features, we attempted to classify Sorani subdialects, showing that sentences from news sources in Iraq and Iran are distinguishable with 96% accuracy. This is the first preliminary study for a dialect that has not been widely studied in computational linguistics, evidencing the possible existence of distinct subdialects.

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Arabic Dialect Identification in Speech Transcripts
Shervin Malmasi | Marcos Zampieri
Proceedings of the Third Workshop on NLP for Similar Languages, Varieties and Dialects (VarDial3)

In this paper we describe a system developed to identify a set of four regional Arabic dialects (Egyptian, Gulf, Levantine, North African) and Modern Standard Arabic (MSA) in a transcribed speech corpus. We competed under the team name MAZA in the Arabic Dialect Identification sub-task of the 2016 Discriminating between Similar Languages (DSL) shared task. Our system achieved an F1-score of 0.51 in the closed training track, ranking first among the 18 teams that participated in the sub-task. Our system utilizes a classifier ensemble with a set of linear models as base classifiers. We experimented with three different ensemble fusion strategies, with the mean probability approach providing the best performance.

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MAZA at SemEval-2016 Task 11: Detecting Lexical Complexity Using a Decision Stump Meta-Classifier
Shervin Malmasi | Marcos Zampieri
Proceedings of the 10th International Workshop on Semantic Evaluation (SemEval-2016)

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LTG at SemEval-2016 Task 11: Complex Word Identification with Classifier Ensembles
Shervin Malmasi | Mark Dras | Marcos Zampieri
Proceedings of the 10th International Workshop on Semantic Evaluation (SemEval-2016)

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Discriminating Similar Languages: Evaluations and Explorations
Cyril Goutte | Serge Léger | Shervin Malmasi | Marcos Zampieri
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

We present an analysis of the performance of machine learning classifiers on discriminating between similar languages and language varieties. We carried out a number of experiments using the results of the two editions of the Discriminating between Similar Languages (DSL) shared task. We investigate the progress made between the two tasks, estimate an upper bound on possible performance using ensemble and oracle combination, and provide learning curves to help us understand which languages are more challenging. A number of difficult sentences are identified and investigated further with human annotation

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Modeling Language Change in Historical Corpora: The Case of Portuguese
Marcos Zampieri | Shervin Malmasi | Mark Dras
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

This paper presents a number of experiments to model changes in a historical Portuguese corpus composed of literary texts for the purpose of temporal text classification. Algorithms were trained to classify texts with respect to their publication date taking into account lexical variation represented as word n-grams, and morphosyntactic variation represented by part-of-speech (POS) distribution. We report results of 99.8% accuracy using word unigram features with a Support Vector Machines classifier to predict the publication date of documents in time intervals of both one century and half a century. A feature analysis is performed to investigate the most informative features for this task and how they are linked to language change.

2015

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Measuring Feature Diversity in Native Language Identification
Shervin Malmasi | Aoife Cahill
Proceedings of the Tenth Workshop on Innovative Use of NLP for Building Educational Applications

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The Jinan Chinese Learner Corpus
Maolin Wang | Shervin Malmasi | Mingxuan Huang
Proceedings of the Tenth Workshop on Innovative Use of NLP for Building Educational Applications

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Oracle and Human Baselines for Native Language Identification
Shervin Malmasi | Joel Tetreault | Mark Dras
Proceedings of the Tenth Workshop on Innovative Use of NLP for Building Educational Applications

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Language Identification using Classifier Ensembles
Shervin Malmasi | Mark Dras
Proceedings of the Joint Workshop on Language Technology for Closely Related Languages, Varieties and Dialects

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Large-Scale Native Language Identification with Cross-Corpus Evaluation
Shervin Malmasi | Mark Dras
Proceedings of the 2015 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Clinical Information Extraction Using Word Representations
Shervin Malmasi | Hamed Hassanzadeh | Mark Dras
Proceedings of the Australasian Language Technology Association Workshop 2015

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Cognate Identification using Machine Translation
Shervin Malmasi | Mark Dras
Proceedings of the Australasian Language Technology Association Workshop 2015

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Norwegian Native Language Identification
Shervin Malmasi | Mark Dras | Irina Temnikova
Proceedings of the International Conference Recent Advances in Natural Language Processing

2014

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Finnish Native Language Identification
Shervin Malmasi | Mark Dras
Proceedings of the Australasian Language Technology Association Workshop 2014

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A Data-driven Approach to Studying Given Names and their Gender and Ethnicity Associations
Shervin Malmasi
Proceedings of the Australasian Language Technology Association Workshop 2014

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Language Transfer Hypotheses with Linear SVM Weights
Shervin Malmasi | Mark Dras
Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing (EMNLP)

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Arabic Native Language Identification
Shervin Malmasi | Mark Dras
Proceedings of the EMNLP 2014 Workshop on Arabic Natural Language Processing (ANLP)

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From Visualisation to Hypothesis Construction for Second Language Acquisition
Shervin Malmasi | Mark Dras
Proceedings of TextGraphs-9: the workshop on Graph-based Methods for Natural Language Processing

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Chinese Native Language Identification
Shervin Malmasi | Mark Dras
Proceedings of the 14th Conference of the European Chapter of the Association for Computational Linguistics, volume 2: Short Papers

2013

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NLI Shared Task 2013: MQ Submission
Shervin Malmasi | Sze-Meng Jojo Wong | Mark Dras
Proceedings of the Eighth Workshop on Innovative Use of NLP for Building Educational Applications