Improving NLTK for Processing Portuguese

Python has a growing community of users, especially in the AI and ML fields. Yet, Computational Processing of Portuguese in this programming language is limited, in both available tools and results. This paper describes NLPyPort, a NLP pipeline in Python, primarily based on NLTK, and focused on Portuguese. It is mostly assembled from pre-existent resources or their adaptations, but improves over the performance of existing alternatives in Python, namely in the tasks of tokenization, PoS tagging, lemmatization and NER

Information Extraction for Event Ranking

Search engines are evolving towards richer and stronger semantic approaches, focusing on entity-oriented tasks where knowledge bases have become fundamental. In order to support semantic search, search engines are increasingly reliant on robust information extraction systems. In fact, most modern search engines are already highly dependent on a well-curated knowledge base. Nevertheless, they still lack the ability to effectively and automatically take advantage of multiple heterogeneous data sources. Central tasks include harnessing the information locked within textual content by linking mentioned entities to a knowledge base, or the integration of multiple knowledge bases to answer natural language questions. Combining text and knowledge bases is frequently used to improve search results, but it can also be used for the query-independent ranking of entities like events. In this work, we present a complete information extraction pipeline for the Portuguese language, covering all stages from data acquisition to knowledge base population. We also describe a practical application of the automatically extracted information, to support the ranking of upcoming events displayed in the landing page of an institutional search engine, where space is limited to only three relevant events. We manually annotate a dataset of news, covering event announcements from multiple faculties and organic units of the institution. We then use it to train and evaluate the named entity recognition module of the pipeline. We rank events by taking advantage of identified entities, as well as partOf relations, in order to compute an entity popularity score, as well as an entity click score based on implicit feedback from clicks from the institutional search engine. We then combine these two scores with the number of days to the event, obtaining a final ranking for the three most relevant upcoming events

Discovery of sensitive data with natural language processing

The process of protecting sensitive data is continually growing and becoming increasingly important, especially as a result of the directives and laws imposed by the European Union. The effort to create automatic systems is continuous, but in most cases, the processes behind them are still manual or semi-automatic. In this work, we have developed a component that can extract and classify sensitive data, from unstructured text information in European Portuguese. The objective was to create a system that allows organizations to understand their data and comply with legal and security purposes. We studied a hybrid approach to the problem of Named Entities Recognition for the Portuguese language. This approach combines several techniques such as rule-based/lexical-based models, machine learning algorithms and neural networks. The rule-based and lexical-based approaches were used only for a set of specific classes. For the remaining classes of entities, SpaCy and Stanford NLP tools were tested, two statistical models – Conditional Random Fields and Random Forest – were implemented and, finally, a Bidirectional- LSTM approach as experimented. The best results were achieved with the Stanford NER model (86.41%), from the Stanford NLP tool. Regarding the statistical models, we realized that Conditional Random Fields is the one that can obtain the best results, with a f1-score of 65.50%. With the Bi-LSTM approach, we have achieved a result of 83.01%. The corpora used for training and testing were HAREM Golden Collection, SIGARRA News Corpus and DataSense NER Corpus.O processo de preservação de dados sensíveis está em constante crescimento e cada vez apresenta maior importância, proveniente especialmente das diretivas e leis impostas pela União Europeia. O esforço para criar sistemas automáticos é contínuo, mas o processo é realizado na maioria dos casos de forma manual ou semiautomática. Neste trabalho desenvolvemos um componente de Extração e Classificação de dados sensíveis, que processa textos não-estruturados em Português Europeu. O objetivo consistiu em criar um sistema que permite às organizações compreender os seus dados e cumprir com fins legais de conformidade e segurança. Para resolver este problema, foi estudada uma abordagem híbrida de Reconhecimento de Entidades Mencionadas para a língua Portuguesa. Esta abordagem combina técnicas baseadas em regras e léxicos, algoritmos de aprendizagem automática e redes neuronais. As primeiras abordagens baseadas em regras e léxicos, foram utilizadas apenas para um conjunto de classes especificas. Para as restantes classes de entidades foram utilizadas as ferramentas SpaCy e Stanford NLP, testados dois modelos estatísticos — Conditional Random Fields e Random Forest – e por fim testada uma abordagem baseada em redes neuronais – Bidirectional-LSTM. Ao nível das ferramentas utilizadas os melhores resultados foram conseguidos com o modelo Stanford NER (86,41%). Através dos modelos estatísticos percebemos que o Conditional Random Fields é o que consegue obter melhores resultados, com um f1-score de 65,50%. Com a última abordagem, uma rede neuronal Bi-LSTM, conseguimos resultado de f1-score de aproximadamente 83,01%. Para o treino e teste das diferentes abordagens foram utilizados os conjuntos de dados HAREM Golden Collection, SIGARRA News Corpus e DataSense NER Corpus

MultiLegalSBD: A Multilingual Legal Sentence Boundary Detection Dataset

Sentence Boundary Detection (SBD) is one of the foundational building blocks of Natural Language Processing (NLP), with incorrectly split sentences heavily influencing the output quality of downstream tasks. It is a challenging task for algorithms, especially in the legal domain, considering the complex and different sentence structures used. In this work, we curated a diverse multilingual legal dataset consisting of over 130’000 annotated sentences in 6 languages. Our experimental results indicate that the performance of existing SBD models is subpar on multilingual legal data. We trained and tested monolingual and multilingual models based on CRF, BiLSTM-CRF, and transformers, demonstrating state-of-the art performance. We also show that our multilingual models outperform all baselines in the zero-shot setting on a Portuguese test set. To encourage further research and development by the community, we have made our dataset, models, and code publicly available

MultiLegalSBD: A Multilingual Legal Sentence Boundary Detection Dataset

Sentence Boundary Detection (SBD) is one of the foundational building blocks of Natural Language Processing (NLP), with incorrectly split sentences heavily influencing the output quality of downstream tasks. It is a challenging task for algorithms, especially in the legal domain, considering the complex and different sentence structures used. In this work, we curated a diverse multilingual legal dataset consisting of over 130'000 annotated sentences in 6 languages. Our experimental results indicate that the performance of existing SBD models is subpar on multilingual legal data. We trained and tested monolingual and multilingual models based on CRF, BiLSTM-CRF, and transformers, demonstrating state-of-the-art performance. We also show that our multilingual models outperform all baselines in the zero-shot setting on a Portuguese test set. To encourage further research and development by the community, we have made our dataset, models, and code publicly available.Comment: Accepted at ICAIL 202

Characterizing the personality of twitter users based on their timeline information

Personality is a set of characteristics that differentiate a person from others. It can be identified by the words that people use in conversations or in publications that they do in social networks. Most existing work focuses on personality prediction analyzing English texts. In this study we analyzed publications of the Portuguese users of the social network Twitter. Taking into account the difficulties in sentiment classification that can be caused by the 140 character limit imposed on tweets, we decided to use different features and methods such as the quantity of followers, friends, locations, publication times, etc. to get a more precise picture of a personality. In this paper, we present methods by which the personality of a user can be predicted without any effort from the Twitter users. The personality can be accurately predicted through the publicly available information on Twitter profiles.A personalidade traduz-se num conjunto de características que diferenciam uma pessoa de outras. Pode ser identificada pelas palavras que as pessoas usam numa conversa ou em publicações que fazem nas redes sociais. A maioria dos trabalhos existentes na literatura estão focados na previsão de personalidade analisando textos em Inglês. Neste estudo, foram analisadas publicações dos utilizadores Portugueses na rede social Twitter. Tendo em conta que o limite de 140 caracteres imposto aos tweets pode dificultar a classificação dos sentimentos dos textos produzidos, foi decidido usar diferentes características e métodos tais como locais, tempo de publicação, quantidade de seguidores, quantidade de amigos, etc., para obter uma imagem mais completa da personalidade. Este documento apresenta um método para fazer a previsão da personalidade de utilizadores do Twitter, com base na informação existente e sem qualquer esforço do lado desses utilizadores. A personalidade pode ser calculada através da informação pública disponível