Experiments on a G uarani Corpus of News and Social Media (2021)

Abstract: While Guarani is widely spoken in South America, obtaining a large amount of Guarani text from the web is hard. We present the building process of a Guarani corpus composed of a parallel Guarani-Spanish set of news articles, and a monolingual set of tweets. We perform some word embeddings experiments aiming at evaluating the quality of the Guarani split of the corpus, finding encouraging results but noticing that more diversity in text domains might be needed for further improvements.

## introduction guarani is a south american language spoken mainly in paraguay, but also in some regions of argentina, bolivia and brazil. despite being an official language of mercosur and paraguay, research and resources for guarani are limited. our work focuses on the current dialect of guarani spoken in paraguay, called jopara. the jopara guarani dialect presents different levels of mixture between guarani and spanish, using mainly the guarani grammar but incorporating many spanish loanwords @xcite . in this work, we present a guarani corpus that tries to reflect the nature of this mixed dialect. on the one hand the corpus contains a set of sentences written in a more formal style, composed of news articles, where each sentence also has a spanish counterpart. on the other hand the corpus has a more informal set of texts extracted from social media; we analyzed them and noticed the different levels of mixture between guarani and other languages. this is a work in progress with the aim of creating resources for guarani that could aid in nlp tasks such as machine translation, so our objective is to make this resource as large as possible but at the same time trying to keep the content quality high. we also show an initial analysis of the cor-pus based on word embeddings analogies tests and visualization. ## related work although guarani remains a little explored language within the nlp community, throughout the years there have been some attempts at creating resources or corpora for this language. coreguapa (secretaría de políticas lingüísticas del paraguay, 2019) is the reference corpus of current paraguayan guarani, it can be queried online but it cannot be downloaded in its entirety. other works have focused on trying to develop machine translation systems or computer aided translation systems for the guarani-spanish pair considering the scarcity of nlp resources for the language (alcaraz and alcaraz, 2020; @xcite @xcite . besides the resources focused on the jopara guarani dialect, there is a small universal dependencies corpus (around a thousand sentences) of the guarani dialect spoken by the mbya guarani people @xcite . the work of @xcite describes the construction of a parallel corpus of guarani and spanish sentences built by downloading pages in both languages from web sources and using an automatic process (with manual correction) to align the sentence pairs. we follow a similar approach in the parallel set of our corpus, although we also add a second set of monolingual text extracted from social media. currently, guarani is included as one of the target languages in the machine translation shared task of the amer-icasnlp workshop, which indicates interest in developing resources for this language is on the rise. ## construction of the corpus this section presents the construction of the parallel and the monolingual sets of the corpus. ## experiments we carried on some experiments to try to analyze the quality of the monolingual split of the corpus built so far. we followed the approach described in @xcite , where they trained a word embeddings collection for spanish from wikipedia text and analyzed its quality based on intrinsic tests and visualization. we trained several variants of 150-dimensional word2vec embeddings collections using the gensim library @xcite . the different variants we trained correspond to using different sets of data. besides the text collected in this work, in our experiments we also used the guarani wikipedia text foot_2 , and the guarani data from @xcite . all models reported here were trained on some combination of those sets, a summary of the sizes of the sets is shown in corpus token count wikipedia 582,122 chiruzzo et al. (2020) 268,684 parallel news set 334,501 reliable tweets set 56,601 unreliable tweets set 453,996 total (reliable tokens) 1,241,908 total (all tokens) 1,695,904 ## conclusions we described the construction of a guarani corpus that contains a parallel news set and a monolingual set of social media texts. we performed word embeddings experiments over different combinations of the data. the visualization experiment showed that the available text is enough to form clusters of words of the same semantic category. the analogies experiments showed that, in some cases, adding our corpus improved the performance, although results for the family test might indicate that more diversity of texts is needed, and text from tweets seems to be too noisy for enhancing the embeddings. as future work, we plan to perform machine translation experiments (in line with the experiments described in @xcite ), which might be a better way of validating the dataset. we think it is important to widen the variety of texts in the corpus: currently the crawling process keeps running daily to collect more text, and it could also be used to collect more data from different sources. now that we have more text available and partially annotated, we can try some statistical approaches such as training a language detector for tweets instead of our keyword list strategy. we think this type of text is relevant, providing a broader and modern usage of jopara guarani, which might aid in other nlp tasks such as sentiment analysis.