A Comparative Framework for Diachronic Lexical Semantic Change in Brazilian Portuguese Political Discourse

João Victor M. Correa, Oto Araújo Vale, Renato Moraes Silva


Abstract
Shifts in political discourse often reflect societal changes, but quantifying how lexical usage and semantic representations vary over time remains a challenge for computational linguistics. To compare approaches under different computational constraints, we propose a cost-aware, modeland language-agnostic framework to compare lexical and semantic change signals. We apply it to Brazilian Portuguese political discourse using a shared panel of lemmas combining drift candidates, stable controls, and theory-driven seeds. We compare three families of diachronic drift signals: a TF-IDF lexical-salience baseline, aligned slice-specific Word2Vec models, and a contextual BERT approach. Results indicate disagreement between cheaper baselines, while contextual BERT remains weakly aligned with each method. A filtered contextual panel reduces stable-control leakage and highlights drift candidates such as “bloqueio” and “salário”. Rather than treating any detector as ground truth, this study presents an exploratory comparison of complementary drift sensitivities, interpretability, and computational cost in Brazilian Portuguese political discourse.
Anthology ID:
2026.stil-1.9
Volume:
Proceedings of the 17th Brazilian Symposium in Information and Human Language Technology
Month:
October
Year:
2026
Address:
Cuiabá, Mato Grosso, Brazil
Editors:
Bryan Khelven da Silva Barbosa, Aline Paes, Ariani Di Felippo
Venue:
STIL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
100–112
Language:
URL:
https://aclanthology.org/2026.stil-1.9/
DOI:
10.5753/stil.2026.23510
Bibkey:
Cite (ACL):
João Victor M. Correa, Oto Araújo Vale, and Renato Moraes Silva. 2026. A Comparative Framework for Diachronic Lexical Semantic Change in Brazilian Portuguese Political Discourse. In Proceedings of the 17th Brazilian Symposium in Information and Human Language Technology, pages 100–112, Cuiabá, Mato Grosso, Brazil. Association for Computational Linguistics.
Cite (Informal):
A Comparative Framework for Diachronic Lexical Semantic Change in Brazilian Portuguese Political Discourse (Correa et al., STIL 2026)
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PDF:
https://aclanthology.org/2026.stil-1.9.pdf