Fernandosr85/afrobr-langbench-adapter

AfroBR-LangBench — Afro-Brazilian Portuguese Sociolinguistics Adapter

LoRA adapter fine-tuned on Llama-4-Scout-17B-16E-Instruct (109B) for respectful sociolinguistic reasoning about Afro-Brazilian Portuguese varieties, via Adaption's AutoScientist platform.

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The problem this adapter addresses

Language models trained on standard text systematically treat Afro-Brazilian Portuguese features as errors rather than documented linguistic phenomena. When given "eles foi lá", a base model typically responds:

"Correction: the correct form is 'eles foram lá'"

The sociolinguistically adequate response is:

"This exemplifies Concordância Verbal Reduzida (CVR), documented in quilombola communities and studied by Lucchesi et al. (2009). Its origin lies in contact between colonial Portuguese and Bantu languages..."

This adapter teaches the model to explain, normalize respectfully, identify, and cite academic sources for 10 documented phenomena.

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Adaptive Data results

Metric	Before	After
Quality score	6.0	9.1
Quality grade	C	A
Relative improvement	—	+51.7%
Percentile (Language domain)	8.2	33.0

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Training metrics

Metric	Value
Base model	meta-llama/Llama-4-Scout-17B-16E-Instruct (109B)
Trained model name	adaption_pt_afro_brasileiro_qa
Training method	SFT + LoRA
LoRA rank (r)	16
LoRA alpha	32
LoRA dropout	0.1
Trainable modules	all-linear
Epochs	4
Training steps	88
Learning rate	7e-5 (cosine scheduler)
Warmup ratio	0.05
Weight decay	0.03
Dataset size	400 examples (Grade A)

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Dataset

Platform	Link
HuggingFace Dataset	Fernandosr85/adaption-pt-afro-brasileiro-qa
Kaggle Dataset	afrobr-langbench-sociolinguistics-dataset
Kaggle Notebook	AfroBR-LangBench

400 instruction-tuning examples across 4 task categories:

Category	Task	Examples
A	Sociolinguistic explanation without prejudice	150
B	Respectful normalization to standard register	100
C	Identification of linguistic phenomena	100
D	RAG-style questions with academic citations	50

10 documented phenomena

Code	Phenomenon
CVR	Concordância Verbal Reduzida
CNR	Concordância Nominal Reduzida
APR	Apagamento do /r/ em coda silábica
TOP	Topicalização com Deslocamento à Esquerda
AGT	Uso de 'a gente' como pronome de 1ª pessoa do plural
NPV	Negação Pós-verbal
MON	Monotongação de Ditongos
PREP	Variação no Uso de Preposições
CLC	Ausência de Clítico Acusativo de 3ª Pessoa
MAA	Marcadores Aspectuais de Origem Africana

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Academic sources

• Lucchesi, D., Baxter, A., Ribeiro, I. (2009). O Português Afro-Brasileiro. EDUFBA.
• Projeto Vertentes (UFBA, 2001–) — speech corpus from quilombola communities in Bahia
• Cyrino, S. (1997). O objeto nulo no Português do Brasil. UNICAMP.
• Galves, C. (2001). Ensaios sobre as gramáticas do português. UNICAMP.
• Schwenter, S. A. (2005). The pragmatics of negation in Brazilian Portuguese. Lingua.
• Holm, J. (2004). Languages in Contact: The Partial Restructuring of Vernaculars. Cambridge University Press.
• Castro, Y. P. (2001). Línguas africanas no Brasil. CEAO/UFBA.

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Credits

• Fine-tuning platform: Adaption — AutoScientist & Adaptive Data
• Challenge: AutoScientist Challenge 2026
• Training infrastructure: Adaption compute credits
• Dataset remastering: Adaption Adaptive Data pipeline (Grade A, +51.7% quality improvement)
• Author: Fernando Rodrigues · Kaggle: fernandosr85 · HuggingFace: Fernandosr85

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Disclaimer

Experimental research artifact submitted to AutoScientist Challenge 2026 (Language category). This adapter is intended for linguistic research and education. It does not represent or speak for Afro-Brazilian communities.