Rafael Valencia-García

Also published as: Rafael Valencia-Garcia


2023

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Overview of Second Shared Task on Homophobia and Transphobia Detection in Social Media Comments
Bharathi Raja Chakravarthi | Rahul Ponnusamy | Malliga S | Paul Buitelaar | Miguel Angel Garc ́ıa-Cumbreras | Salud Mar ́ıa Jimenez-Zafra | Jose Antonio Garcia-Diaz | Rafael Valencia-Garcia | Nitesh Jindal
Proceedings of the Third Workshop on Language Technology for Equality, Diversity and Inclusion

We present an overview of the second shared task on homophobia/transphobia Detection in social media comments. Given a comment, a system must predict whether or not it contains any form of homophobia/transphobia. The shared task included five languages: English, Spanish, Tamil, Hindi, and Malayalam. The data was given for two tasks. Task A was given three labels, and Task B fine-grained seven labels. In total, 75 teams enrolled for the shared task in Codalab. For task A, 12 teams submitted systems for English, eight teams for Tamil, eight teams for Spanish, and seven teams for Hindi. For task B, nine teams submitted for English, 7 teams for Tamil, 6 teams for Malayalam. We present and analyze all submissions in this paper.

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Overview of the Shared Task on Hope Speech Detection for Equality, Diversity, and Inclusion
Prasanna Kumar Kumaresan | Bharathi Raja Chakravarthi | Subalalitha Cn | Miguel Ángel García-Cumbreras | Salud María Jiménez Zafra | José Antonio García-Díaz | Rafael Valencia-García | Momchil Hardalov | Ivan Koychev | Preslav Nakov | Daniel García-Baena | Kishore Kumar Ponnusamy
Proceedings of the Third Workshop on Language Technology for Equality, Diversity and Inclusion

Hope serves as a powerful driving force that encourages individuals to persevere in the face of the unpredictable nature of human existence. It instills motivation within us to remain steadfast in our pursuit of important goals, regardless of the uncertainties that lie ahead. In today’s digital age, platforms such as Facebook, Twitter, Instagram, and YouTube have emerged as prominent social media outlets where people freely express their views and opinions. These platforms have also become crucial for marginalized individuals seeking online assistance and support[1][2][3]. The outbreak of the pandemic has exacerbated people’s fears around the world, as they grapple with the possibility of losing loved ones and the lack of access to essential services such as schools, hospitals, and mental health facilities.

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UMUTeam at SemEval-2023 Task 12: Ensemble Learning of LLMs applied to Sentiment Analysis for Low-resource African Languages
José Antonio García-Díaz | Camilo Caparros-laiz | Ángela Almela | Gema Alcaráz-Mármol | María José Marín-Pérez | Rafael Valencia-García
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

These working notes summarize the participation of the UMUTeam in the SemEval 2023 shared task: AfriSenti, focused on Sentiment Analysis in several African languages. Two subtasks are proposed, one in which each language is considered separately and another one in which all languages are merged. Our proposal to solve both subtasks is grounded on the combination of features extracted from several multilingual Large Language Models and a subset of language-independent linguistic features. Our best results are achieved with the African languages less represented in the training set: Xitsonga, a Mozambique dialect, with a weighted f1-score of 54.89\%; Algerian Arabic, with a weighted f1-score of 68.52\%; Swahili, with a weighted f1-score of 60.52\%; and Twi, with a weighted f1-score of 71.14%.

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UMUTeam and SINAI at SemEval-2023 Task 9: Multilingual Tweet Intimacy Analysis using Multilingual Large Language Models and Data Augmentation
José Antonio García-Díaz | Ronghao Pan | Salud María Jiménez Zafra | María-Teresa Martn-Valdivia | L. Alfonso Ureña-López | Rafael Valencia-García
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

This work presents the participation of the UMUTeam and the SINAI research groups in the SemEval-2023 Task 9: Multilingual Tweet Intimacy Analysis. The goal of this task is to predict the intimacy of a set of tweets in 10 languages: English, Spanish, Italian, Portuguese, French, Chinese, Hindi, Arabic, Dutch and Korean, of which, the last 4 are not in the training data. Our approach to address this task is based on data augmentation and the use of three multilingual Large Language Models (multilingual BERT, XLM and mDeBERTA) by ensemble learning. Our team ranked 30th out of 45 participants. Our best results were achieved with two unseen languages: Korean (16th) and Hindi (19th).

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UMUTeam at SemEval-2023 Task 10: Fine-grained detection of sexism in English
Ronghao Pan | José Antonio García-Díaz | Salud María Jiménez Zafra | Rafael Valencia-García
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

In this manuscript, we describe the participation of UMUTeam in the Explainable Detection of Online Sexism shared task proposed at SemEval 2023. This task concerns the precise and explainable detection of sexist content on Gab and Reddit, i.e., developing detailed classifiers that not only identify what is sexist, but also explain why it is sexism. Our participation in the three EDOS subtasks is based on extending new unlabeled sexism data in the Masked Language Model task of a pre-trained model, such as RoBERTa-large to improve its generalization capacity and its performance on classification tasks. Once the model has been pre-trained with the new data, fine-tuning of this model is performed for different specific sexism classification tasks. Our system has achieved excellent results in this competitive task, reaching top 24 (84) in Task A, top 23 (69) in Task B, and top 13 (63) in Task C.

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UMUTeam at SemEval-2023 Task 3: Multilingual transformer-based model for detecting the Genre, the Framing, and the Persuasion Techniques in Online News
Ronghao Pan | José Antonio García-Díaz | Miguel Ángel Rodríguez-García | Rafael Valencia-García
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

In this manuscript, we describe the participation of the UMUTeam in SemEval-2023 Task 3, a shared task on detecting different aspects of news articles and other web documents, such as document category, framing dimensions, and persuasion technique in a multilingual setup. The task has been organized into three related subtasks, and we have been involved in the first two. Our approach is based on a fine-tuned multilingual transformer-based model that uses the dataset of all languages at once and a sentence transformer model to extract the most relevant chunk of a text for subtasks 1 and 2. The input data was truncated to 200 tokens with 50 overlaps using the sentence-transformer model to obtain the subset of text most related to the articles’ titles. Our system has performed good results in subtask 1 in most languages, and in some cases, such as French and German, we have archived first place in the official leader board. As for task 2, our system has also performed very well in all languages, ranking in all the top 10.

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Chick Adams at SemEval-2023 Task 5: Using RoBERTa and DeBERTa to Extract Post and Document-based Features for Clickbait Spoiling
Ronghao Pan | José Antonio García-Díaz | Franciso García-Sánchez | Rafael Valencia-García
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

In this manuscript, we describe the participation of the UMUTeam in SemEval-2023 Task 5, namely, Clickbait Spoiling, a shared task on identifying spoiler type (i.e., a phrase or a passage) and generating short texts that satisfy curiosity induced by a clickbait post, i.e. generating spoilers for the clickbait post. Our participation in Task 1 is based on fine-tuning pre-trained models, which consists in taking a pre-trained model and tuning it to fit the spoiler classification task. Our system has obtained excellent results in Task 1: we outperformed all proposed baselines, being within the Top 10 for most measures. Foremost, we reached Top 3 in F1 score in the passage spoiler ranking.

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UMUTeam at SemEval-2023 Task 11: Ensemble Learning applied to Binary Supervised Classifiers with disagreements
José Antonio García-Díaz | Ronghao Pan | Gema Alcaráz-Mármol | María José Marín-Pérez | Rafael Valencia-García
Proceedings of the 17th International Workshop on Semantic Evaluation (SemEval-2023)

This paper describes the participation of the UMUTeam in the Learning With Disagreements (Le-Wi-Di) shared task proposed at SemEval 2023, which objective is the development of supervised automatic classifiers that consider, during training, the agreements and disagreements among the annotators of the datasets. Specifically, this edition includes a multilingual dataset. Our proposal is grounded on the development of ensemble learning classifiers that combine the outputs of several Large Language Models. Our proposal ranked position 18 of a total of 30 participants. However, our proposal did not incorporate the information about the disagreements. In contrast, we compare the performance of building several classifiers for each dataset separately with a merged dataset.

2022

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UMUTextStats: A linguistic feature extraction tool for Spanish
José Antonio García-Díaz | Pedro José Vivancos-Vicente | Ángela Almela | Rafael Valencia-García
Proceedings of the Thirteenth Language Resources and Evaluation Conference

Feature Engineering consists in the application of domain knowledge to select and transform relevant features to build efficient machine learning models. In the Natural Language Processing field, the state of the art concerning automatic document classification tasks relies on word and sentence embeddings built upon deep learning models based on transformers that have outperformed the competition in several tasks. However, the models built from these embeddings are usually difficult to interpret. On the contrary, linguistic features are easy to understand, they result in simpler models, and they usually achieve encouraging results. Moreover, both linguistic features and embeddings can be combined with different strategies which result in more reliable machine-learning models. The de facto tool for extracting linguistic features in Spanish is LIWC. However, this software does not consider specific linguistic phenomena of Spanish such as grammatical gender and lacks certain verb tenses. In order to solve these drawbacks, we have developed UMUTextStats, a linguistic extraction tool designed from scratch for Spanish. Furthermore, this tool has been validated to conduct different experiments in areas such as infodemiology, hate-speech detection, author profiling, authorship verification, humour or irony detection, among others. The results indicate that the combination of linguistic features and embeddings based on transformers are beneficial in automatic document classification.

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UMUTeam at SemEval-2022 Task 5: Combining image and textual embeddings for multi-modal automatic misogyny identification
José García-Díaz | Camilo Caparros-Laiz | Rafael Valencia-García
Proceedings of the 16th International Workshop on Semantic Evaluation (SemEval-2022)

In this manuscript we describe the participation of the UMUTeam on the MAMI shared task proposed at SemEval 2022. This task is concerning the identification of misogynous content from a multi-modal perspective. Our participation is grounded on the combination of different feature sets within the same neural network. Specifically, we combine linguistic features with contextual transformers based on text (BERT) and images (BEiT). Besides, we also evaluate other ensemble learning strategies and the usage of non-contextual pretrained embeddings. Although our results are limited, we outperform all the baselines proposed, achieving position 36 in the binary classification task with a macro F1-score of 0.687, and position 28 in the multi-label task of misogynous categorisation, with an macro F1-score of 0.663.

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UMUTeam at SemEval-2022 Task 6: Evaluating Transformers for detecting Sarcasm in English and Arabic
José García-Díaz | Camilo Caparros-Laiz | Rafael Valencia-García
Proceedings of the 16th International Workshop on Semantic Evaluation (SemEval-2022)

In this manuscript we detail the participation of the UMUTeam in the iSarcasm shared task (SemEval-2022). This shared task is related to the identification of sarcasm in English and Arabic documents. Our team achieve in the first challenge, a binary classification task, a F1 score of the sarcastic class of 17.97 for English and 31.75 for Arabic. For the second challenge, a multi-label classification, our results are not recorded due to an unknown problem. Therefore, we report the results of each sarcastic mechanism with the validation split. For our proposal, several neural networks that combine language-independent linguistic features with pre-trained embeddings are trained. The embeddings are based on different schemes, such as word and sentence embeddings, and contextual and non-contextual embeddings. Besides, we evaluate different techniques for the integration of the feature sets, such as ensemble learning and knowledge integration. In general, our best results are achieved using the knowledge integration strategy.

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UMUTeam@LT-EDI-ACL2022: Detecting homophobic and transphobic comments in Tamil
José García-Díaz | Camilo Caparros-Laiz | Rafael Valencia-García
Proceedings of the Second Workshop on Language Technology for Equality, Diversity and Inclusion

This working-notes are about the participation of the UMUTeam in a LT-EDI shared task concerning the identification of homophobic and transphobic comments in YouTube. These comments are written in English, which has high availability to machine-learning resources; Tamil, which has fewer resources; and a transliteration from Tamil to Roman script combined with English sentences. To carry out this shared task, we train a neural network that combines several feature sets applying a knowledge integration strategy. These features are linguistic features extracted from a tool developed by our research group and contextual and non-contextual sentence embeddings. We ranked 7th for English subtask (macro f1-score of 45%), 3rd for Tamil subtask (macro f1-score of 82%), and 2nd for Tamil-English subtask (macro f1-score of 58%).

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UMUTeam@LT-EDI-ACL2022: Detecting Signs of Depression from text
José García-Díaz | Rafael Valencia-García
Proceedings of the Second Workshop on Language Technology for Equality, Diversity and Inclusion

Depression is a mental condition related to sadness and the lack of interest in common daily tasks. In this working-notes, we describe the proposal of the UMUTeam in the LT-EDI shared task (ACL 2022) concerning the identification of signs of depression in social network posts. This task is somehow related to other relevant Natural Language Processing tasks such as Emotion Analysis. In this shared task, the organisers challenged the participants to distinguish between moderate and severe signs of depression (or no signs of depression at all) in a set of social posts written in English. Our proposal is based on the combination of linguistic features and several sentence embeddings using a knowledge integration strategy. Our proposal achieved the 6th position, with a macro f1-score of 53.82 in the official leader board.

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Overview of the Shared Task on Hope Speech Detection for Equality, Diversity, and Inclusion
Bharathi Raja Chakravarthi | Vigneshwaran Muralidaran | Ruba Priyadharshini | Subalalitha Cn | John McCrae | Miguel Ángel García | Salud María Jiménez-Zafra | Rafael Valencia-García | Prasanna Kumaresan | Rahul Ponnusamy | Daniel García-Baena | José García-Díaz
Proceedings of the Second Workshop on Language Technology for Equality, Diversity and Inclusion

Hope Speech detection is the task of classifying a sentence as hope speech or non-hope speech given a corpus of sentences. Hope speech is any message or content that is positive, encouraging, reassuring, inclusive and supportive that inspires and engenders optimism in the minds of people. In contrast to identifying and censoring negative speech patterns, hope speech detection is focussed on recognising and promoting positive speech patterns online. In this paper, we report an overview of the findings and results from the shared task on hope speech detection for Tamil, Malayalam, Kannada, English and Spanish languages conducted in the second workshop on Language Technology for Equality, Diversity and Inclusion (LT-EDI-2022) organised as a part of ACL 2022. The participants were provided with annotated training & development datasets and unlabelled test datasets in all the five languages. The goal of the shared task is to classify the given sentences into one of the two hope speech classes. The performances of the systems submitted by the participants were evaluated in terms of micro-F1 score and weighted-F1 score. The datasets for this challenge are openly available

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UMUTeam@TamilNLP-ACL2022: Emotional Analysis in Tamil
José García-Díaz | Miguel Ángel Rodríguez García | Rafael Valencia-García
Proceedings of the Second Workshop on Speech and Language Technologies for Dravidian Languages

This working notes summarises the participation of the UMUTeam on the TamilNLP (ACL 2022) shared task concerning emotion analysis in Tamil. We participated in the two multi-classification challenges proposed with a neural network that combines linguistic features with different feature sets based on contextual and non-contextual sentence embeddings. Our proposal achieved the 1st result for the second subtask, with an f1-score of 15.1% discerning among 30 different emotions. However, our results for the first subtask were not recorded in the official leader board. Accordingly, we report our results for this subtask with the validation split, reaching a macro f1-score of 32.360%.

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UMUTeam@TamilNLP-ACL2022: Abusive Detection in Tamil using Linguistic Features and Transformers
José García-Díaz | Manuel Valencia-Garcia | Rafael Valencia-García
Proceedings of the Second Workshop on Speech and Language Technologies for Dravidian Languages

Social media has become a dangerous place as bullies take advantage of the anonymity the Internet provides to target and intimidate vulnerable individuals and groups. In the past few years, the research community has focused on developing automatic classification tools for detecting hate-speech, its variants, and other types of abusive behaviour. However, these methods are still at an early stage in low-resource languages. With the aim of reducing this barrier, the TamilNLP shared task has proposed a multi-classification challenge for Tamil written in Tamil script and code-mixed to detect abusive comments and hope-speech. Our participation consists of a knowledge integration strategy that combines sentence embeddings from BERT, RoBERTa, FastText and a subset of language-independent linguistic features. We achieved our best result in code-mixed, reaching 3rd position with a macro-average f1-score of 35%.

2021

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UMUTeam at SemEval-2021 Task 7: Detecting and Rating Humor and Offense with Linguistic Features and Word Embeddings
José Antonio García-Díaz | Rafael Valencia-García
Proceedings of the 15th International Workshop on Semantic Evaluation (SemEval-2021)

In writing, humor is mainly based on figurative language in which words and expressions change their conventional meaning to refer to something without saying it directly. This flip in the meaning of the words prevents Natural Language Processing from revealing the real intention of a communication and, therefore, reduces the effectiveness of tasks such as Sentiment Analysis or Emotion Detection. In this manuscript we describe the participation of the UMUTeam in HaHackathon 2021, whose objective is to detect and rate humorous and controversial content. Our proposal is based on the combination of linguistic features with contextual and non-contextual word embeddings. We participate in all the proposed subtasks achieving our best result in the controversial humor subtask.

2012

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Seeing through Deception: A Computational Approach to Deceit Detection in Written Communication
Ángela Almela | Rafael Valencia-García | Pascual Cantos
Proceedings of the Workshop on Computational Approaches to Deception Detection