Xabier Saralegi

Also published as: X. Saralegi


2021

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GEPSA, a tool for monitoring social challenges in digital press
Iñaki San Vicente | Xabier Saralegi | Nerea Zubia
Proceedings of the First Workshop on Language Technology for Equality, Diversity and Inclusion

This papers presents a platform for monitoring press narratives with respect to several social challenges, including gender equality, migrations and minority languages. As narratives are encoded in natural language, we have to use natural processing techniques to automate their analysis. Thus, crawled news are processed by means of several NLP modules, including named entity recognition, keyword extraction,document classification for social challenge detection, and sentiment analysis. A Flask powered interface provides data visualization for a user-based analysis of the data. This paper presents the architecture of the system and describes in detail its different components. Evaluation is provided for the modules related to extraction and classification of information regarding social challenges.

2020

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Elhuyar submission to the Biomedical Translation Task 2020 on terminology and abstracts translation
Ander Corral | Xabier Saralegi
Proceedings of the Fifth Conference on Machine Translation

This article describes the systems submitted by Elhuyar to the 2020 Biomedical Translation Shared Task, specifically the systems presented in the subtasks of terminology translation for English-Basque and abstract translation for English-Basque and English-Spanish. In all cases a Transformer architecture was chosen and we studied different strategies to combine open domain data with biomedical domain data for building the training corpora. For the English-Basque pair, given the scarcity of parallel corpora in the biomedical domain, we set out to create domain training data in a synthetic way. The systems presented in the terminology and abstract translation subtasks for the English-Basque language pair ranked first in their respective tasks among four participants, achieving 0.78 accuracy for terminology translation and a BLEU of 0.1279 for the translation of abstracts. In the abstract translation task for the English-Spanish pair our team ranked second (BLEU=0.4498) in the case of OK sentences.

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Building a Task-oriented Dialog System for Languages with no Training Data: the Case for Basque
Maddalen López de Lacalle | Xabier Saralegi | Iñaki San Vicente
Proceedings of the 12th Language Resources and Evaluation Conference

This paper presents an approach for developing a task-oriented dialog system for less-resourced languages in scenarios where training data is not available. Both intent classification and slot filling are tackled. We project the existing annotations in rich-resource languages by means of Neural Machine Translation (NMT) and posterior word alignments. We then compare training on the projected monolingual data with direct model transfer alternatives. Intent Classifiers and slot filling sequence taggers are implemented using a BiLSTM architecture or by fine-tuning BERT transformer models. Models learnt exclusively from Basque projected data provide better accuracies for slot filling. Combining Basque projected train data with rich-resource languages data outperforms consistently models trained solely on projected data for intent classification. At any rate, we achieve competitive performance in both tasks, with accuracies of 81% for intent classification and 77% for slot filling.

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Give your Text Representation Models some Love: the Case for Basque
Rodrigo Agerri | Iñaki San Vicente | Jon Ander Campos | Ander Barrena | Xabier Saralegi | Aitor Soroa | Eneko Agirre
Proceedings of the 12th Language Resources and Evaluation Conference

Word embeddings and pre-trained language models allow to build rich representations of text and have enabled improvements across most NLP tasks. Unfortunately they are very expensive to train, and many small companies and research groups tend to use models that have been pre-trained and made available by third parties, rather than building their own. This is suboptimal as, for many languages, the models have been trained on smaller (or lower quality) corpora. In addition, monolingual pre-trained models for non-English languages are not always available. At best, models for those languages are included in multilingual versions, where each language shares the quota of substrings and parameters with the rest of the languages. This is particularly true for smaller languages such as Basque. In this paper we show that a number of monolingual models (FastText word embeddings, FLAIR and BERT language models) trained with larger Basque corpora produce much better results than publicly available versions in downstream NLP tasks, including topic classification, sentiment classification, PoS tagging and NER. This work sets a new state-of-the-art in those tasks for Basque. All benchmarks and models used in this work are publicly available.

2016

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Evaluating Translation Quality and CLIR Performance of Query Sessions
Xabier Saralegi | Eneko Agirre | Iñaki Alegria
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

This paper presents the evaluation of the translation quality and Cross-Lingual Information Retrieval (CLIR) performance when using session information as the context of queries. The hypothesis is that previous queries provide context that helps to solve ambiguous translations in the current query. We tested several strategies on the TREC 2010 Session track dataset, which includes query reformulations grouped by generalization, specification, and drifting types. We study the Basque to English direction, evaluating both the translation quality and CLIR performance, with positive results in both cases. The results show that the quality of translation improved, reducing error rate by 12% (HTER) when using session information, which improved CLIR results 5% (nDCG). We also provide an analysis of the improvements across the three kinds of sessions: generalization, specification, and drifting. Translation quality improved in all three types (generalization, specification, and drifting), and CLIR improved for generalization and specification sessions, preserving the performance in drifting sessions.

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Polarity Lexicon Building: to what Extent Is the Manual Effort Worth?
Iñaki San Vicente | Xabier Saralegi
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Polarity lexicons are a basic resource for analyzing the sentiments and opinions expressed in texts in an automated way. This paper explores three methods to construct polarity lexicons: translating existing lexicons from other languages, extracting polarity lexicons from corpora, and annotating sentiments Lexical Knowledge Bases. Each of these methods require a different degree of human effort. We evaluate how much manual effort is needed and to what extent that effort pays in terms of performance improvement. Experiment setup includes generating lexicons for Basque, and evaluating them against gold standard datasets in different domains. Results show that extracting polarity lexicons from corpora is the best solution for achieving a good performance with reasonable human effort.

2015

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EliXa: A Modular and Flexible ABSA Platform
Iñaki San Vicente | Xabier Saralegi | Rodrigo Agerri
Proceedings of the 9th International Workshop on Semantic Evaluation (SemEval 2015)

2012

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Building a Basque-Chinese Dictionary by Using English as Pivot
Xabier Saralegi | Iker Manterola | Iñaki San Vicente
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

Bilingual dictionaries are key resources in several fields such as translation, language learning or various NLP tasks. However, only major languages have such resources. Automatically built dictionaries by using pivot languages could be a useful resource in these circumstances. Pivot-based bilingual dictionary building is based on merging two bilingual dictionaries which share a common language (e.g. LA-LB, LB-LC) in order to create a dictionary for a new language pair (e.g LA-LC). This process may include wrong translations due to the polisemy of words. We built Basque-Chinese (Mandarin) dictionaries automatically from Basque-English and Chinese-English dictionaries. In order to prune wrong translations we used different methods adequate for less resourced languages. Inverse Consultation and Distributional Similarity methods are used because they just depend on easily available resources. Finally, we evaluated manually the quality of the built dictionaries and the adequacy of the methods. Both Inverse Consultation and Distributional Similarity provide good precision of translations but recall is seriously damaged. Distributional similarity prunes rare translations more accurately than other methods.

2011

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Analyzing Methods for Improving Precision of Pivot Based Bilingual Dictionaries
Xabier Saralegi | Iker Manterola | Iñaki San Vicente
Proceedings of the 2011 Conference on Empirical Methods in Natural Language Processing

2010

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Dictionary and Monolingual Corpus-based Query Translation for Basque-English CLIR
Xabier Saralegi | Maddalen Lopez de Lacalle
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

This paper deals with the main problems that arise in the query translation process in dictionary-based Cross-lingual Information Retrieval (CLIR): translation selection, presence of Out-Of-Vocabulary (OOV) terms and translation of Multi-Word Expressions (MWE). We analyse to what extent each problem affects the retrieval performance for the Basque-English pair of languages, and the improvement obtained when using parallel corpora free methods to address them. To tackle the translation selection problem we provide novel extensions of an already existing monolingual target co-occurrence-based method, the Out-Of Vocabulary terms are dealt with by means of a cognate detection-based method and finally, for the Multi-Word Expression translation problem, a naïve matching technique is applied. The error analysis shows significant differences in the deterioration of the performance depending on the problem, in terms of Mean Average Precision (MAP), the translation selection problem being the cause of most of the errors. Otherwise, the proposed combined strategy shows a good performance to tackle the three above-mentioned main problems.

2004

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A XML-Based Term Extraction Tool for Basque
I. Alegria | A. Gurrutxaga | P. Lizaso | X. Saralegi | S. Ugartetxea | R. Urizar
Proceedings of the Fourth International Conference on Language Resources and Evaluation (LREC’04)

This project combines linguistic and statistical information to develop a term extraction tool for Basque. Being Basque an agglutinative and highly inflected language, the treatment of morphosyntactic information is vital. In addition, due to late unification process of the language, texts present more elevated term dispersion than in a highly normalized language. The result is a semi-automatic terminology extraction tool based on XML, for its use in technical and scientific information managing.