Pedro Henrique Luz De Araujo

Also published as: Pedro Henrique Luz de Araujo, Pedro Henrique Luz de Araujo


2024

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Proceedings of the 20th Conference on Natural Language Processing (KONVENS 2024)
Pedro Henrique Luz de Araujo | Andreas Baumann | Dagmar Gromann | Brigitte Krenn | Benjamin Roth | Michael Wiegand
Proceedings of the 20th Conference on Natural Language Processing (KONVENS 2024)

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Functionality learning through specification instructions
Pedro Henrique Luz De Araujo | Benjamin Roth
Findings of the Association for Computational Linguistics: EMNLP 2024

Test suites assess natural language processing models’ performance on specific functionalities: cases of interest involving model robustness, fairness, or particular linguistic capabilities. This paper introduces specification instructions: text descriptions specifying fine-grained task-specific behaviors. For each functionality in a suite, we generate an instruction that describes it. We combine the specification instructions to create specification-augmented prompts, which we feed to language models pre-trained on natural instruction data.We conduct experiments to measure how optimizing for some functionalities may negatively impact functionalities that are not covered by the specification set. Our analyses across four tasks and models of diverse sizes and families show that smaller models struggle to follow specification instructions. However, larger models (> 3B params.) can benefit from specifications and—surprisingly—even generalize certain desirable behaviors across functionalities.

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Text-Guided Alternative Image Clustering
Andreas Stephan | Lukas Miklautz | Collin Leiber | Pedro Henrique Luz De Araujo | Dominik Répás | Claudia Plant | Benjamin Roth
Proceedings of the 9th Workshop on Representation Learning for NLP (RepL4NLP-2024)

Traditional image clustering techniques only find a single grouping within visual data. In particular, they do not provide a possibility to explicitly define multiple types of clustering. This work explores the potential of large vision-language models to facilitate alternative image clustering. We propose Text-Guided Alternative Image Consensus Clustering (TGAICC), a novel approach that leverages user-specified interests via prompts to guide the discovery of diverse clusterings. To achieve this, it generates a clustering for each prompt, groups them using hierarchical clustering, and then aggregates them using consensus clustering. TGAICC outperforms image- and text-based baselines on four alternative image clustering benchmark datasets. Furthermore, using count-based word statistics, we are able to obtain text-based explanations of the alternative clusterings. In conclusion, our research illustrates how contemporary large vision-language models can transform explanatory data analysis, enabling the generation of insightful, customizable, and diverse image clusterings.

2023

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Cross-functional Analysis of Generalization in Behavioral Learning
Pedro Henrique Luz de Araujo | Benjamin Roth
Transactions of the Association for Computational Linguistics, Volume 11

In behavioral testing, system functionalities underrepresented in the standard evaluation setting (with a held-out test set) are validated through controlled input-output pairs. Optimizing performance on the behavioral tests during training (behavioral learning) would improve coverage of phenomena not sufficiently represented in the i.i.d. data and could lead to seemingly more robust models. However, there is the risk that the model narrowly captures spurious correlations from the behavioral test suite, leading to overestimation and misrepresentation of model performance—one of the original pitfalls of traditional evaluation. In this work, we introduce BeLUGA, an analysis method for evaluating behavioral learning considering generalization across dimensions of different granularity levels. We optimize behavior-specific loss functions and evaluate models on several partitions of the behavioral test suite controlled to leave out specific phenomena. An aggregate score measures generalization to unseen functionalities (or overfitting). We use BeLUGA to examine three representative NLP tasks (sentiment analysis, paraphrase identification, and reading comprehension) and compare the impact of a diverse set of regularization and domain generalization methods on generalization performance.1

2022

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Checking HateCheck: a cross-functional analysis of behaviour-aware learning for hate speech detection
Pedro Henrique Luz de Araujo | Benjamin Roth
Proceedings of NLP Power! The First Workshop on Efficient Benchmarking in NLP

Behavioural testing—verifying system capabilities by validating human-designed input-output pairs—is an alternative evaluation method of natural language processing systems proposed to address the shortcomings of the standard approach: computing metrics on held-out data. While behavioural tests capture human prior knowledge and insights, there has been little exploration on how to leverage them for model training and development. With this in mind, we explore behaviour-aware learning by examining several fine-tuning schemes using HateCheck, a suite of functional tests for hate speech detection systems. To address potential pitfalls of training on data originally intended for evaluation, we train and evaluate models on different configurations of HateCheck by holding out categories of test cases, which enables us to estimate performance on potentially overlooked system properties. The fine-tuning procedure led to improvements in the classification accuracy of held-out functionalities and identity groups, suggesting that models can potentially generalise to overlooked functionalities. However, performance on held-out functionality classes and i.i.d. hate speech detection data decreased, which indicates that generalisation occurs mostly across functionalities from the same class and that the procedure led to overfitting to the HateCheck data distribution.

2020

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VICTOR: a Dataset for Brazilian Legal Documents Classification
Pedro Henrique Luz de Araujo | Teófilo Emídio de Campos | Fabricio Ataides Braz | Nilton Correia da Silva
Proceedings of the Twelfth Language Resources and Evaluation Conference

This paper describes VICTOR, a novel dataset built from Brazil’s Supreme Court digitalized legal documents, composed of more than 45 thousand appeals, which includes roughly 692 thousand documents—about 4.6 million pages. The dataset contains labeled text data and supports two types of tasks: document type classification; and theme assignment, a multilabel problem. We present baseline results using bag-of-words models, convolutional neural networks, recurrent neural networks and boosting algorithms. We also experiment using linear-chain Conditional Random Fields to leverage the sequential nature of the lawsuits, which we find to lead to improvements on document type classification. Finally we compare a theme classification approach where we use domain knowledge to filter out the less informative document pages to the default one where we use all pages. Contrary to the Court experts’ expectations, we find that using all available data is the better method. We make the dataset available in three versions of different sizes and contents to encourage explorations of better models and techniques.