RacismoBR: A Manually Annotated Dataset for Racist Discourse Detection in Brazilian Portuguese
Paper · 2026 · João Vítor Vaz, Fabrício Benevenuto and Marcos André Gonçalves
Summary
Racism detection in Brazilian Portuguese has few dedicated resources. Existing Portuguese corpora usually fold racism into general hate speech, and their annotation guidelines are often borrowed from other cultural settings. The authors present RacismoBR, a small corpus of posts and replies from X. They collected it with targeted keyword sampling, and Black researchers labeled every item as racist or non-racist, so the labels rest on lived and sociolinguistic expertise.
On this data, they compared three families of classifiers under one controlled protocol:
- classical machine learning,
- fine-tuned Transformer Small Language Models,
- instruction-tuned LLMs prompted with few-shot examples.
GPT-4.1 and BERTimbau reached the best Macro-F1. However, Wilcoxon signed-rank tests found no significant differences between models, largely because results varied a lot. Error analysis shows that implicit, euphemistic and context-dependent racism trips up all paradigms in similar ways. The authors conclude that careful, culturally informed annotation and dataset design matter more than larger architectures, and they argue for keeping humans in the moderation loop.
Key points
- Data collection: 405 posts and replies were gathered from X via the paid API between September 2024 and January 2025. Keywords included "mulambo", "racismo", "racista", "candomblé", "africano/a" and "neguinho/a".
- Annotation: eight Black researchers, working in four independent pairs, labeled the data in two classes (racist = 1, non-racist = 0). They followed a definition of racism adapted from Almeida (2019).
- Results: GPT-4.1 and BERTimbau scored highest on Macro-F1, but Wilcoxon tests showed no statistically significant gap across paradigms.
- Shared pattern: all models had higher precision on non-racist posts and higher recall on racist posts.
- Availability and scope: the dataset is on GitHub (joaovitorvaz/RacismoBR-Dataset) under responsible disclosure. It covers single-turn texts and racism against Black people only.
Fields, topics and concepts
📚 Shelves 2The field of science this work belongs to (OpenAlex fields).Computer Science · 18,614 worksArtificial Intelligence · 17,965 works
🧭 Topics 1Research subjects and languages the work is about.Discourse analysis · 471 works
Cite
Cite as João Vítor Vaz, Fabrício Benevenuto and Marcos André Gonçalves. 2026. RacismoBR: A Manually Annotated Dataset for Racist Discourse Detection in Brazilian Portuguese. Proceedings of the 17th International Conference on Computational Processing of Portuguese (PROPOR 2026) - Vol. 1.
@inproceedings{vaz2026racismobr,
title = {{RacismoBR: A Manually Annotated Dataset for Racist Discourse Detection in Brazilian Portuguese}},
author = {João Vítor Vaz, Fabrício Benevenuto and Marcos André Gonçalves},
booktitle = {Proceedings of the 17th International Conference on Computational Processing of Portuguese (PROPOR 2026) - Vol. 1},
year = {2026},
url = {https://aclanthology.org/2026.propor-1.76/}
}References
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