Data-Faithful Natural Language Generation for Explaining Fitness-Market Anomalies

Kauan Divino Pouso Mariano, Fabrycio Leite Nakano Almada, Victor Emanuel da Silva Monteiro, Maykon Adriell Dutra, Jefferson Felex de Faria, Jennifer Vitória da Silva Peixoto, Kamylla Sejane Pouso Freitas


Abstract
This study presents an integrated pipeline that transforms anomaly-detection outputs from global fitness-market data into data-faithful narratives. Using a 132-country panel and a 2019 baseline, we analyze observed post-COVID-19 recovery through 2025, while treating 2026 only as a modelled extension. Four complementary detectors—regional-median deviations, linear-regression residuals, Random Forest residuals, and Isolation Forest—are combined through method agreement and mapped to a rule-based typology. A deterministic, template-based Natural Language Generation (NLG) component then produces short, medium, and complete explanations from tabular evidence. In 2025, 14 countries were consensus anomalies; Guyana exemplified market growth without participatory expansion, with revenue recovery of +401.43%, participation recovery of -2.06%, and a 403.50-point gap. All 132 narratives passed automatic factual-consistency checks. These checks validate field preservation rather than fluency, usefulness, or explanatory quality; human evaluation remains future work.
Anthology ID:
2026.stil-1.50
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:
567–572
Language:
URL:
https://aclanthology.org/2026.stil-1.50/
DOI:
10.5753/stil.2026.29472
Bibkey:
Cite (ACL):
Kauan Divino Pouso Mariano, Fabrycio Leite Nakano Almada, Victor Emanuel da Silva Monteiro, Maykon Adriell Dutra, Jefferson Felex de Faria, Jennifer Vitória da Silva Peixoto, and Kamylla Sejane Pouso Freitas. 2026. Data-Faithful Natural Language Generation for Explaining Fitness-Market Anomalies. In Proceedings of the 17th Brazilian Symposium in Information and Human Language Technology, pages 567–572, Cuiabá, Mato Grosso, Brazil. Association for Computational Linguistics.
Cite (Informal):
Data-Faithful Natural Language Generation for Explaining Fitness-Market Anomalies (Mariano et al., STIL 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.stil-1.50.pdf