The objective of the research we present is to remedy the problem of the low quality of language models for low-resource languages. We introduce an algorithm, the Token Embedding Mapping Algorithm (TEMA), that maps the token embeddings of a richly pre-trained model L1 to a poorly trained model L2, thus creating a richer L2’ model. Our experiments show that the L2’ model reduces perplexity with respect to the original monolingual model L2, and that for downstream tasks, including SuperGLUE, the results are state-of-the-art or better for the most semantic tasks. The models obtained with TEMA are also competitive or better than multilingual or extended models proposed as solutions for mitigating the low-resource language problems.
The paper presents the results of the ParlaMint II project, which comprise comparable corpora of parliamentary debates of 29 European countries and autonomous regions, covering at least the period from 2015 to 2022, and containing over 1 billion words. The corpora are uniformly encoded, contain rich metadata about their 24 thousand speakers, and are linguistically annotated up to the level of Universal Dependencies syntax and named entities. The paper focuses on the enhancement made since the ParlaMint I project and presents the compilation of the corpora, including the encoding infrastructure, use of GitHub, the production of individual corpora, the common pipeline for producing their distribution, and use of CLARIN services for dissemination. It then gives a quantitative overview of the produced corpora, followed by the qualitative additions made within the ParlaMint II project, namely metadata localisation, the addition of new metadata, such as the political orientation of political parties, the machine translation of the corpora to English and its tagging with semantic classes, and the production of pilot speech corpora. Finally, outreach activities and further work are discussed.
We introduce CatCoLA, the Catalan Corpus of Linguistic Acceptabilitythat will contribute to the Catalan Language Understanding Benchmark (CLUB)to assess and compare the capabilities of language models (LM) trained with textsin Catalan. CatCoLA follows the design of the English CoLA to support the task ofclassifying sentences as acceptable or not. Because the task is very dependent on thecharacteristics of particular languages, datasets cannot be translated from one lan-guage to another and the availability of these datasets for different languages requiresspecific developments. CatCoLA consists of 10,443 sentences and their acceptabilityjudgements as found in well-known Catalan reference grammars. Additionally, allsentences have been annotated with the class of linguistic phenomenon the sentenceis an example of, also following previous practices. We also provide as task base-lines the results of fine-tuning four different language models with this dataset andthe results of a human annotation experiment. The results are also analyzed andcommented to guide future research. CatCoLA is released under a CC BY SA 4.0licence and freely available
We present a comprehensive and valuable resource in the form of an aligned parallel corpus comprising translations of the Bible in Spanish. Our collection encompasses a total of eleven Bibles, originating from diverse centuries (XVI, XIX, XX), various religious denominations (Protestant, Catholic), and geographical regions (Spain, Latin America). The process of aligning the verses across these translations has been meticulously carried out, ensuring that the content is organized in a coherent manner. As a result, this corpus serves as a useful convenient resource for various linguistic analyses, including paraphrase detection, semantic clustering, and the exploration of biases present within the texts. To illustrate the utility of this resource, we provide several examples that demonstrate how it can be effectively employed in these applications.
BACKGROUND:Decline in language has emerged as a new potential biomarker for the early detection of Alzheimer's disease (AD). It remains unclear how sensitive language measures are across different tasks, language domains, and languages, and to what extent changes can be reliably detected in early stages such as subjective cognitive decline (SCD) and mild cognitive impairment (MCI).METHOD:Using a scene construction task for speech elicitation in a new Spanish/Catalan speaking cohort (N = 119), we automatically extracted features across seven domains, three acoustic (spectral, cepstral, and voice quality), one prosodic, and three from text (morpholexical, semantic, and syntactic). They were forwarded to a random forest classifier to evaluate the discriminability of participants with probable AD dementia, amnestic and nonamnestic MCI, SCD, and cognitively healthy controls. Repeated-measures analyses of variance and paired-samples Wilcoxon signed-ranks test were used to assess whether and how performance differs significantly across groups and linguistic domains.RESULTS:The performance scores of the machine learning classifier were generally satisfactorily high, with the highest scores over .9. Model performance was significantly different for linguistic domains (p < .001), and speech versus text (p = .043), with speech features outperforming textual features, and voice quality performing best. High diagnostic classification accuracies were seen even within both cognitively healthy (controls vs. SCD) and MCI (amnestic and nonamnestic) groups.CONCLUSION:Speech-based machine learning is powerful in detecting cognitive decline and probable AD dementia across a range of different feature domains, though important differences exist between these domains as well.SUPPLEMENTAL MATERIAL:https://doi.org/10.23641/asha.23699733.
This paper reports on the experiments aimed to improve our understanding of the role of the amount of data required for training attention-based transformer language models. Specifically, we investigate the impact of reducing the immense amounts of required pre-training data through sampling strategies that identify and reduce high-frequency tokens as different studies have indicated that the existence of very high-frequency tokens in pre-training data might bias learning, causing undesired effects. In this light, we describe our sampling algorithm that iteratively assesses token frequencies and removes sentences that contain still high-frequency tokens, eventually delivering a balanced, linguistically correct dataset. We evaluate the results in terms of model perplexity and fine-tuning linguistic probing tasks, NLP downstream tasks as well as more semantic SuperGlue tasks. The results show that pre-training with the resulting balanced dataset allows reducing up to three times the pre-training data.
Language Models (LM) are becoming more and more useful for providing representations upon which to train Natural Language Processing applications. However, there is now clear evidence that attention-based transformers require a critical amount of language data to produce good enough LMs. The question we have addressed in this paper is to what extent the critical amount of data varies for languages of different morphological typology, in particular those that have a rich inflectional morphology, and whether the tokenization method to preprocess the data can make a difference. These details can be important for low-resourced languages that need to plan the production of datasets. We evaluated intrinsically and extrinsically the differences of five different languages with different pretraining dataset sizes and three different tokenization methods for each. The results confirm that the size of the vocabulary due to morphological characteristics is directly correlated with both the LM perplexity and the performance of two typical downstream tasks such as NER identification and POS labeling. The experiments also provide new evidence that a canonical tokenizer can reduce perplexity by more than a half for a polysynthetic language like Quechua as well as raising F1 from 0.8 to more than 0.9 in both downstream tasks with a LM trained with only 6M tokens.
Parliamentary speeches are considered to be of interest for different research areas because they are publicly available transcriptions, produced under controlled and regulated procedures that add totally reliable sociodemographic data like gender, age, and other details of the speakers. Moreover, speeches are rich in topics and domains, and they are actually public domain data, not subject to copyright restrictions. The ParlaMint project: Towards Comparable Parliamentary Corpora is developing a comparable and uniformly annotated multilingual corpus with the data from 33 different parliaments in Europe. This paper describes the details of building the ParlaMintCAT corpus, for which the transcriptions of the Catalan Parliament General Assembly sessions from 2015 to 2022 have been compiled, processed and annotated.
With the deployment of Electronic Health Records, much effort is being devoted to the development of Natural Language Processing tools that convert information described in these clinical records into structured data to be exploited. Clinical records main characteristic is that they are free text. They are normally written under pressure as memory notes and contain a high number of abbreviations that are an issue for automatic processing. In this article we present the IULA Spanish Clinical Records Corpus annotated for abbreviation identification.
Automatic Speech Recognition (ASR) is a key element in new services that helps users to interact with an automated system. Deep learning methods have made it possible to deploy systems with word error rates below 5% for ASR of English. However, the use of these methods is only available for languages with hundreds or thousands of hours of audio and their corresponding transcriptions. For the so-called low-resource languages to speed up the availability of resources that can improve the performance of their ASR systems, methods of creating new resources on the basis of existing ones are being investigated. In this paper we describe our data augmentation approach to improve the results of ASR models for low-resource and agglutinative languages. We carry out experiments developing an ASR for Quechua using the wav2letter++ model. We reduced WER by 8.73% through our approach to the base model. The resulting ASR model obtained 22.75% WER and was trained with 99 hours of original resources and 99 hours of synthetic data obtained with a combination of text augmentation and synthetic speech generation.
Rodolfo Zevallos, John Ortega, William Chen, Richard Castro, Núria Bel, Cesar Toshio, Renzo Venturas, Hilario Aradiel and Nelsi Melgarejo. Proceedings of the Third Workshop on Deep Learning for Low-Resource Natural Language Processing. 2022.
The goal of our research was to assess whether the observation about deceptive texts having a lower positive tone than truthful ones in terms of sentiment could become operative and be used for building a classifier in the particular case of fraudster’s letters written in Spanish. The data were the letters that CEOs address to company shareholders in their annual financial reports, and the task was to identify the letters of companies that committed financial misconduct or fraud. This case was challenging for two reasons: first, most of the research worked with spontaneous written or spoken texts, while these letters did not; second, most of the research in this area worked on English texts, while we validated the linguistic cues found as evidence of deception for Spanish texts. The results of our research confirm that an SVM trained with a bag-of-words model of frequent adjectives can achieve 81% accuracy because these adjectives bring the information about which positive or negative tone and which word combinations in a text turn out to be a characteristic of fraudster’s texts.
Multilingualism is a cultural cornerstone of Europe and firmly anchored in the European treaties including full language equality. However, language barriers impacting business, cross-lingual and cross-cultural communication are still omnipresent. Language Technologies (LTs) are a powerful means to break down these barriers. While the last decade has seen various initiatives that created a multitude of approaches and technologies tailored to Europe's specific needs, there is still an immense level of fragmentation. At the same time, AI has become an increasingly important concept in the European Information and Communication Technology area. For a few years now, AI, including many opportunities, synergies but also misconceptions, has been overshadowing every other topic. We present an overview of the European LT landscape, describing funding programmes, activities, actions and challenges in the different countries with regard to LT, including the current state of play in industry and the LT market. We present a brief overview of the main LT-related activities on the EU level in the last ten years and develop strategic guidance with regard to four key dimensions.
The TUNER coordinated project (2016-2018) has focused on the development of domain adaptation technologies that reduce the cost of creating linguistic resources to develop systems in different languages and for different domains and genres. In this article we present the demonstrators, prototypes and resources that are already available project results.
Bilingual electronic dictionaries contain collections of lexical entries in two languages, with explicitly declared translation relations between such entries. Nevertheless, they are typically developed in isolation, in their own formats and accessible through proprietary APIs. In this paper we propose the use of Semantic Web techniques to make translations available on the Web to be consumed by other semantic enabled resources in a direct manner, based on standard languages and query means. In particular, we describe the conversion of the Apertium family of bilingual dictionaries and lexicons into RDF (Resource Description Framework) and how their data have been made accessible on the Web as linked data. As a result, all the converted dictionaries (many of them covering under-resourced languages) are connected among them and can be easily traversed from one to another to obtain, for instance, translations between language pairs not originally connected in any of the original dictionaries.
Aspect identification in user generated texts by supervised text classification might suffer degradation in performance when changing to other domains than the one used for training. For referring to aspects such as quality, price or customer services the vocabulary might differ and affect performance. In this paper, we present an experiment to validate a method to handle domain shifts when there is no available labeled data to retrain. The system is based on the offset method as used for solving word analogy problems in vector semantic models such as word embedding. Despite of the fact that the offset method indeed found relevant analogues in the new domain for the classifier initial selected features, the classifiers did not deliver the expected results. The analysis showed that a number of words were found as analogues for many different initial features. This phenomenon was already described in the literature as 'default words' or 'hubs'. However, our data showed that it cannot be explained in terms of word frequency or distance to the question word, as suggested.
This paper presents the IULA Spanish Clinical Record Corpus, a corpus of 3,194 sentences extracted from anonymized clinical records and manually annotated with negation markers and their scope. The corpus was conceived as a resource to support clinical text-mining systems, but it is also a useful resource for other Natural Language Processing systems handling clinical texts: automatic encoding of clinical records, diagnosis support, term extraction, among others, as well as for the study of clinical texts. The corpus is publicly available with a CC-BY-SA 3.0 license.
This work was supported by the Spanish CIEN project LPS-BIGGER cofunded by the MINECO and CDTI (IDI-20141260) and TUNER project TIN2015-65308-C5-5-R (MINECO/FEDER, UE).
In this work we present an experiment for enriching a Statistical Machine Translation (SMT) phrase table with automatically created bilingual word pairs. The bilingual lexicon is induced with a supervised classifier trained using a joint representation of word embeddings (WE) and Brown clusters (BC) of translation equivalent word pairs as features. The classifier reaches a 0.94 F-score and the MT experiment results show an improvement of up to +0.70 BLEU over a low resource Chinese-Spanish phrase-based SMT baseline, demonstrating that bad entries delivered by the classifier are well handled.