Detecting syntactic errors in dependency treebanks for morphosyntactically rich languages

Abstract. The paper introduces a new method for detecting and correcting errors in large dependency treebanks with rich morphosyntactic annotation. The technique uses error correction rules automatically extracted from the treebank. The procedure of rule extraction is based on a comparison of similar -but not identical -subgraphs of dependency structures. The outcome of applying the method to a 3-million-sentence dependency treebank of Polish is presented and evaluated. The method achieves satisfactory precision in the task of automatic error correction and relatively high precision in the task of error detection

Increased recall in annotation variance detection in treebanks

Automatic inconsistency detection in parsed corpora is significantly helpful for building more and larger corpora of annotated texts. Inconsistencies are inevitable and originate from variance in annotation caused by different factors as, for instance, the lack of attention or the absence of clear annotation guidelines. In this paper, some results involving the automatic detection of annotation variance in parsed corpora are presented. In particular, it is shown that a generalization procedure substantially increases the recall of the variant detection algorithm proposed in [1]930257858618th International Conference on Text, Speech and Dialogue (TSD)2015-09República ChecaInt Speech Commun Assoc; Czech Soc Cybernet & Informat; Kerio Technol; Univ West Bohemia, Fac Appl Sci; Masaryk Univ, Fac InformatPilse

Annotation, exploitation and evaluation of parallel corpora

Exchange between the translation studies and the computational linguistics communities has traditionally not been very intense. Among other things, this is reflected by the different views on parallel corpora. While computational linguistics does not always strictly pay attention to the translation direction (e.g. when translation rules are extracted from (sub)corpora which actually only consist of translations), translation studies are amongst other things concerned with exactly comparing source and target texts (e.g. to draw conclusions on interference and standardization effects). However, there has recently been more exchange between the two fields – especially when it comes to the annotation of parallel corpora. This special issue brings together the different research perspectives. Its contributions show – from both perspectives – how the communities have come to interact in recent years

Dependency Syntax in the Automatic Detection of Irony and Stance

[ES] The present thesis is part of the broad panorama of studies of Natural Language Processing (NLP). In particular, it is a work of Computational Linguistics (CL) designed to study in depth the contribution of syntax in the field of sentiment analysis and, therefore, to study texts extracted from social media or, more generally, online content. Furthermore, given the recent interest of the scientific community in the Universal Dependencies (UD) project, which proposes a morphosyntactic annotation format aimed at creating a "universal" representation of the phenomena of morphology and syntax in a manifold of languages, in this work we made use of this format, thinking of a study in a multilingual perspective (Italian, English, French and Spanish). In this work we will provide an exhaustive presentation of the morphosyntactic annotation format of UD, in particular underlining the most relevant issues regarding their application to UGC. Two tasks will be presented, and used as case studies, in order to test the research hypotheses: the first case study will be in the field of automatic Irony Detection and the second in the area of Stance Detection. In both cases, historical notes will be provided that can serve as a context for the reader, an introduction to the problems faced will be outlined and the activities proposed in the computational linguistics community will be described. Furthermore, particular attention will be paid to the resources currently available as well as to those developed specifically for the study of the aforementioned phenomena. Finally, through the description of a series of experiments, both within evaluation campaigns and within independent studies, I will try to describe the contribution that syntax can provide to the resolution of such tasks. This thesis is a revised collection of my three-year PhD career and collocates within the growing trend of studies devoted to make Artificial Intelligence results more explainable, going beyond the achievement of highest scores in performing tasks, but rather making their motivations understandable and comprehensible for experts in the domain. The novel contribution of this work mainly consists in the exploitation of features that are based on morphology and dependency syntax, which were used in order to create vectorial representations of social media texts in various languages and for two different tasks. Such features have then been paired with a manifold of machine learning classifiers, with some neural networks and also with the language model BERT. Results suggest that fine-grained dependency-based syntactic information is highly informative for the detection of irony, and less informative for what concerns stance detection. Nonetheless, dependency syntax might still prove useful in the task of stance detection if firstly irony detection is considered as a preprocessing step. I also believe that the dependency syntax approach that I propose could shed some light on the explainability of a difficult pragmatic phenomenon such as irony.[CA] La presente tesis se enmarca dentro del amplio panorama de estudios relacionados con el Procesamiento del Lenguaje Natural (NLP). En concreto, se trata de un trabajo de Lingüística Computacional (CL) cuyo objetivo principal es estudiar en profundidad la contribución de la sintaxis en el campo del análisis de sentimientos y, en concreto, aplicado a estudiar textos extraídos de las redes sociales o, más en general, de contenidos online. Además, dado el reciente interés de la comunidad científica por el proyecto Universal Dependencies (UD), en el que se propone un formato de anotación morfosintáctica destinado a crear una representación "universal" de la morfología y sintaxis aplicable a diferentes idiomas, en este trabajo se utiliza este formato con el propósito de realizar un estudio desde una perspectiva multilingüe (italiano, inglés, francés y español). En este trabajo se presenta una descripción exhaustiva del formato de anotación morfosintáctica de UD, en particular, subrayando las cuestiones más relevantes en cuanto a su aplicación a los UGC generados en las redes sociales. El objetivo final es analizar y comprobar si estas anotaciones morfosintácticas sirven para obtener información útil para los modelos de detección de la ironía y del stance o posicionamiento. Se presentarán dos tareas y se utilizarán como ejemplos de estudio para probar las hipótesis de la investigación: el primer caso se centra en el área de la detección automática de la ironía y el segundo en el área de la detección del stance o posicionamiento. En ambos casos, se proporcionan los antecendentes y trabajos relacionados notas históricas que pueden servir de contexto para el lector, se plantean los problemas encontrados y se describen las distintas actividades propuestas para resolver estos problemas en la comunidad de la lingüística computacional. Se presta especial atención a los recursos actualmente disponibles, así como a los desarrollados específicamente para el estudio de los fenómenos antes mencionados. Finalmente, a través de la descripción de una serie de experimentos, llevados a cabo tanto en campañas de evaluación como en estudios independientes, se describe la contribución que la sintaxis puede brindar a la resolución de esas tareas. Esta tesis es el resultado de toda la investigación que he llevado a cabo durante mi doctorado en una colección revisada de mi carrera de doctorado de los últimos tres años y medio, y se ubica dentro de la tendencia creciente de estudios dedicados a hacer que los resultados de la Inteligencia Artificial sean más explicables, yendo más allá del logro de puntajes más altos en la realización de tareas, sino más bien haciendo comprensibles sus motivaciones y qué los procesos sean más comprensibles para los expertos en el dominio. La contribución principal y más novedosa de este trabajo consiste en la explotación de características (o rasgos) basadas en la morfología y la sintaxis de dependencias, que se utilizaron para crear las representaciones vectoriales de textos procedentes de redes sociales en varios idiomas y para dos tareas diferentes. A continuación, estas características se han combinado con una variedad de clasificadores de aprendizaje automático, con algunas redes neuronales y también con el modelo de lenguaje BERT. Los resultados sugieren que la información sintáctica basada en dependencias utilizada es muy informativa para la detección de la ironía y menos informativa en lo que respecta a la detección del posicionamiento. No obstante, la sintaxis basada en dependencias podría resultar útil en la tarea de detección del posicionamiento si, en primer lugar, la detección de ironía se considera un paso previo al procesamiento en la detección del posicionamiento. También creo que el enfoque basado casi completamente en sintaxis de dependencias que propongo en esta tesis podría ayudar a explicar mejor un fenómeno prag[EN] La present tesi s'emmarca dins de l'ampli panorama d'estudis relacionats amb el Processament del Llenguatge Natural (NLP). En concret, es tracta d'un treball de Lingüística Computacional (CL), l'objectiu principal del qual és estudiar en profunditat la contribució de la sintaxi en el camp de l'anàlisi de sentiments i, en concret, aplicat a l'estudi de textos extrets de les xarxes socials o, més en general, de continguts online. A més, el recent interès de la comunitat científica pel projecte Universal Dependències (UD), en el qual es proposa un format d'anotació morfosintàctica destinat a crear una representació "universal" de la morfologia i sintaxi aplicable a diferents idiomes, en aquest treball s'utilitza aquest format amb el propòsit de realitzar un estudi des d'una perspectiva multilingüe (italià, anglès, francès i espanyol). En aquest treball es presenta una descripció exhaustiva del format d'anotació morfosintàctica d'UD, en particular, posant més èmfasi en les qüestions més rellevants pel que fa a la seva aplicació als UGC generats a les xarxes socials. L'objectiu final és analitzar i comprovar si aquestes anotacions morfosintàctiques serveixen per obtenir informació útil per als sistemes de detecció de la ironia i del stance o posicionament. Es presentaran dues tasques i s'utilitzaran com a exemples d'estudi per provar les hipòtesis de la investigació: el primer cas se centra en l'àrea de la detecció automàtica de la ironia i el segon en l'àrea de la detecció del stance o posicionament. En tots dos casos es proporcionen els antecedents i treballs relacionats que poden servir de context per al lector, es plantegen els problemes trobats i es descriuen les diferents activitats proposades per resoldre aquests problemes en la comunitat de la lingüística computacional. Es fa especialment referència als recursos actualment disponibles, així com als desenvolupats específicament per a l'estudi dels fenòmens abans esmentats. Finalment, a través de la descripció d'una sèrie d'experiments, duts a terme tant en campanyes d'avaluació com en estudis independents, es descriu la contribució que la sintaxi pot oferir a la resolució d'aquestes tasques. Aquesta tesi és el resultat de tota la investigació que he dut a terme durant el meu doctorat els últims tres anys i mig, i se situa dins de la tendència creixent d'estudis dedicats a fer que els resultats de la Intel·ligència Artificial siguin més explicables, que vagin més enllà de l'assoliment de puntuacions més altes en la realització de tasques, sinó més aviat fent comprensibles les seves motivacions i què els processos siguin més comprensibles per als experts en el domini. La contribució principal i més nova d'aquest treball consisteix en l'explotació de característiques (o trets) basades en la morfologia i la sintaxi de dependències, que s'utilitzen per crear les representacions vectorials de textos procedents de xarxes socials en diversos idiomes i per a dues tasques diferents. A continuació, aquestes característiques s'han combinat amb una varietat de classificadors d'aprenentatge automàtic, amb algunes xarxes neuronals i també amb el model de llenguatge BERT. Els resultats suggereixen que la informació sintàctica utilitzada basada en dependències és molt informativa per a la detecció de la ironia i menys informativa pel que fa a la detecció del posicionament. Malgrat això, la sintaxi basada en dependències podria ser útil en la tasca de detecció del posicionament si, en primer lloc, la detecció d'ironia es considera un pas previ al processament en la detecció del posicionament. També crec que l'enfocament basat gairebé completament en sintaxi de dependències que proposo en aquesta tesi podria ajudar a explicar millor un fenomen pragmàtic tan difícil de detectar i d'interpretar com la ironia.Cignarella, AT. (2021). Dependency Syntax in the Automatic Detection of Irony and Stance [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/177639TESI

Representation and parsing of multiword expressions

This book consists of contributions related to the definition, representation and parsing of MWEs. These reflect current trends in the representation and processing of MWEs. They cover various categories of MWEs such as verbal, adverbial and nominal MWEs, various linguistic frameworks (e.g. tree-based and unification-based grammars), various languages including English, French, Modern Greek, Hebrew, Norwegian), and various applications (namely MWE detection, parsing, automatic translation) using both symbolic and statistical approaches

Current trends

Deep parsing is the fundamental process aiming at the representation of the syntactic structure of phrases and sentences. In the traditional methodology this process is based on lexicons and grammars representing roughly properties of words and interactions of words and structures in sentences. Several linguistic frameworks, such as Headdriven Phrase Structure Grammar (HPSG), Lexical Functional Grammar (LFG), Tree Adjoining Grammar (TAG), Combinatory Categorial Grammar (CCG), etc., offer different structures and combining operations for building grammar rules. These already contain mechanisms for expressing properties of Multiword Expressions (MWE), which, however, need improvement in how they account for idiosyncrasies of MWEs on the one hand and their similarities to regular structures on the other hand. This collaborative book constitutes a survey on various attempts at representing and parsing MWEs in the context of linguistic theories and applications

Multiword expressions at length and in depth

The annual workshop on multiword expressions takes place since 2001 in conjunction with major computational linguistics conferences and attracts the attention of an ever-growing community working on a variety of languages, linguistic phenomena and related computational processing issues. MWE 2017 took place in Valencia, Spain, and represented a vibrant panorama of the current research landscape on the computational treatment of multiword expressions, featuring many high-quality submissions. Furthermore, MWE 2017 included the first shared task on multilingual identification of verbal multiword expressions. The shared task, with extended communal work, has developed important multilingual resources and mobilised several research groups in computational linguistics worldwide. This book contains extended versions of selected papers from the workshop. Authors worked hard to include detailed explanations, broader and deeper analyses, and new exciting results, which were thoroughly reviewed by an internationally renowned committee. We hope that this distinctly joint effort will provide a meaningful and useful snapshot of the multilingual state of the art in multiword expressions modelling and processing, and will be a point point of reference for future work

Modeling the interface between morphology and syntax in data-driven dependency parsing

When people formulate sentences in a language, they follow a set of rules specific to that language that defines how words must be put together in order to express the intended meaning. These rules are called the grammar of the language. Languages have essentially two ways of encoding grammatical information: word order or word form. English uses primarily word order to encode different meanings, but many other languages change the form of the words themselves to express their grammatical function in the sentence. These languages are commonly subsumed under the term morphologically rich languages. Parsing is the automatic process for predicting the grammatical structure of a sentence. Since grammatical structure guides the way we understand sentences, parsing is a key component in computer programs that try to automatically understand what people say and write. This dissertation is about parsing and specifically about parsing languages with a rich morphology, which encode grammatical information in the form of words. Today’s parsing models for automatic parsing were developed for English and achieve good results on this language. However, when applied to other languages, a significant drop in performance is usually observed. The standard model for parsing is a pipeline model that separates the parsing process into different steps, in particular it separates the morphological analysis, i.e. the analysis of word forms, from the actual parsing step. This dissertation argues that this separation is one of the reasons for the performance drop of standard parsers when applied to other languages than English. An analysis is presented that exposes the connection between the morphological system of a language and the errors of a standard parsing model. In a second series of experiments, we show that knowledge about the syntactic structure of sentence can support the prediction of morphological information. We then argue for an alternative approach that models morphological analysis and syntactic analysis jointly instead of separating them. We support this argumentation with empirical evidence by implementing two parsers that model the relationship between morphology and syntax in two different but complementary ways

Proceedings of the Seventh International Conference Formal Approaches to South Slavic and Balkan languages

Proceedings of the Seventh International Conference Formal Approaches to South Slavic and Balkan Languages publishes 17 papers that were presented at the conference organised in Dubrovnik, Croatia, 4-6 Octobre 2010

Annotation, exploitation and evaluation of parallel corpora: TC3 I

Exchange between the translation studies and the computational linguistics communities has traditionally not been very intense. Among other things, this is reflected by the different views on parallel corpora. While computational linguistics does not always strictly pay attention to the translation direction (e.g. when translation rules are extracted from (sub)corpora which actually only consist of translations), translation studies are amongst other things concerned with exactly comparing source and target texts (e.g. to draw conclusions on interference and standardization effects). However, there has recently been more exchange between the two fields – especially when it comes to the annotation of parallel corpora. This special issue brings together the different research perspectives. Its contributions show – from both perspectives – how the communities have come to interact in recent years