Marcelo Finger

Author directory

2026

Alternatives to Large Language Models have been proposed to develop smaller models that require substantially less training data. In this paper, we propose a monolingual (Portuguese) Hybrid Transformer model trained with only 260M words, whose size is comparable to that of small Encoder-based models. After pre-training, we fine-tune our model and compare it against 11 existing models on the AES-ENEM dataset — an Automatic Essay Scoring benchmark in which models are required to evaluate five distinct textual dimensions. Our experiments demonstrate that our model is always competitive with the (bigger) best available model, despite its smaller scale.
Este estudo descreve o desenvolvimento de uma ferramenta de inteligência artificial para identificar e classificar discursos racistas e sexistas proferidos por agentes jurídicos. Focado em processos de violência sexual do Tribunal de Justiça de São Paulo (TJSP), a pesquisa visa evidenciar vieses que corroboram a vitimização secundária. A solução computacional baseia-se em um modelo de Processamento de Linguagem Natural com arquitetura Transformer, utilizando um modelo derivado do BERT pré-treinado para o português brasileiro. O modelo é treinado com dados textuais categorizados por uma ontologia de estereótipos de gênero e seu desempenho é avaliado por validação cruzada (k = 5) com métricas de acurácia, precisão, revocação e medida-F.
Compression-based linguistic complexity metrics enable cross-linguistic comparison without prior annotation. Their sensitivity to variation across languages and Portuguese registers highlights their applicability in NLP tasks. This study investigates their use as readability proxies and complementary features in Automatic Essay Scoring. We analyze how these metrics capture variation in essay quality across traits, genres, and educational levels in Brazilian Portuguese. In addition, we evaluate their sensitivity to differences between humanand AI-generated essays. Our results suggest that complexity metrics are effective (i) in differentiating educational levels, (ii) in detecting whether they were written by humans and (iii) as predictors of essay quality.
Sub-word tokenizers allow us to handle open vocabulary problems using a relatively small set of tokens. Despite its ease of use, it usually relies on a data-driven approach that does not directly employ linguistic or morphologic features for text tokenization. [Bostrom and Durrett 2020] and [Hofmann et al. 2021] demonstrate that morphemes improve LLM performance on English texts. In this work, we explore the hypothesis that tokenizers that are capable of producing a token sequence better aligned with a morpheme sequence can improve LLMs performance on Brazilian Portuguese. To evaluate how the presence of morphemes can impact LLMs for Brazilian Portuguese, we propose MorphEval-PT, a new evaluation procedure based on the psycholinguistic concept of morphological models of word processing. We build new BPE and Unigram vocabularies that are evaluated on MorphEval-PT and, in order to validate the impact of morphemes on LLMs performance, train new LLMs from scratch and evaluate its performance on downstream tasks. Consistently, BPE demonstrates a higher precision score than Unigram in its ability to represent morphemes, as well as better performance on every downstream task. These promising results indicate that accessing the ability of tokenizers to represent morphemes is an important feature in the development of LLMs for Brazilian Portuguese and that MorphEval-PT is a good and lightweight method to improve LLM performance before any pre-training.
Asthma is a chronic respiratory disease that affects breathing and may also influence speech and voice production. In this paper, we examine whether short mobile-recorded Brazilian Portuguese voice and speech audio contain cues that can be used to distinguish individuals with asthma from those without asthma. We approach this problem using transfer learning with pretrained neural audio models based on convolutional architectures trained on large-scale audio datasets (PANNs). We evaluate two recording types: sustained vowel phonation and read speech. Models are trained for a binary classification task and evaluated at both the segment level and the patient level. Read speech performs better than sustained vowels. The best configuration (CNN14 on speech) achieves 0.85 patient-level balanced accuracy (accuracy 0.85) with ROC-AUC 0.93 and PR-AUC 0.98, performing comparably to CNN10. Training from scratch performs worse than fine-tuning a pretrained model, showing that pretraining helps when data is limited. Performance also varies across age groups, suggesting demographic sensitivity. These findings support the feasibility of audio-based asthma classification from voice and speech and motivate further investigation of pretrained audio models in biomedical applications.
Compression-based language complexity metrics show promise as holistic parameters for measuring linguistic complexity across intra- and cross-linguistic scenarios. Yet, their sensitivity to specific forms of linguistic variation requires further experimental validation. We examine the sensitivity of this metric family to register variation in Portuguese, a phenomenon already established for English. We refine the validation process found in previous literature by introducing a more granular statistical analysis to evaluate both the individual and joint sensitivity of these metrics to register variation at the sentence level. Our results confirm they are highly sensitive to functional variation in Portuguese, exhibiting the same structural morphosyntactic trade-off consistent with that observed in English and in cross-linguistic studies.
While scaling laws suggest increasing model and dataset sizes for better results, efficient pre-training techniques for low-resource scenarios present unique challenges that require further investigation. This work introduces FlexQwen, a model based on the Qwen 3 architecture adapted for a hybrid causal-masked objective, and the Carolina Originality dataset, a subset of the Corpus Carolina tailored for efficient pre-training in Portuguese. We investigate two primary research questions: the influence of hybrid masked-causal modelling and the impact of text originality on model performance. Our experiments compare a high-originality Gold split against a length-matched control group. Results indicate that hybrid objectives may be viable for efficient training. Furthermore, we provide open access to our code, datasets, and training logs to foster further research in efficient Portuguese LLMs.

2024

Language complexity is an emerging concept critical for NLP and for quantitative and cognitive approaches to linguistics. In this work, we evaluate the behavior of a set of compression-based language complexity metrics when applied to a large set of native South American languages. Our goal is to validate the desirable properties of such metrics against a more diverse set of languages, guaranteeing the universality of the techniques developed on the basis of this type of theoretical artifact. Our analysis confirmed with statistical confidence most propositions about the metrics studied, affirming their robustness, despite showing less stability than when the same metrics were applied to Indo-European languages. We also observed that the trade-off between morphological and syntactic complexities is strongly related to language phylogeny.

2021

2019

At present, different deep learning models are presenting high accuracy on popular inference datasets such as SNLI, MNLI, and SciTail. However, there are different indicators that those datasets can be exploited by using some simple linguistic patterns. This fact poses difficulties to our understanding of the actual capacity of machine learning models to solve the complex task of textual inference. We propose a new set of syntactic tasks focused on contradiction detection that require specific capacities over linguistic logical forms such as: Boolean coordination, quantifiers, definite description, and counting operators. We evaluate two kinds of deep learning models that implicitly exploit language structure: recurrent models and the Transformer network BERT. We show that although BERT is clearly more efficient to generalize over most logical forms, there is space for improvement when dealing with counting operators. Since the syntactic tasks can be implemented in different languages, we show a successful case of cross-lingual transfer learning between English and Portuguese.

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