Repository for the EACL 2026 paper "SrcMix: Mixing of Related Source Languages Benefits Extremely Low-resource Machine Translation". Contains the dataset and code for SrcMix, a controlled source-language mixing approach for extremely low-resource machine translation.
# SrcMix: Mixing of Related Source Languages Benefits Extremely Low-resource Machine Translation
📢 **Accepted to EACL 2026 (Findings)**
Official implementation of **SrcMix**, a simple and effective
training-time strategy for improving machine translation in **Extremely
Low-Resource Languages (ELRLs)**.
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## Motivation
Extremely low-resource languages (ELRLs) often suffer from:
- Fewer than 6K parallel sentences
- Limited supervision
- High typological diversity
- Weak transfer from massively multilingual models
Standard multilingual training (naïve concatenation or many-to-many setups) Often performs poorly in ELRL settings due to:
- Negative transfer
- Cross-lingual interference
- Fragmented decoder supervision
**SrcMix** addresses this by introducing multilinguality only on the
*source side*, while keeping the decoder specialized to a single target
ELRL.
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## What is SrcMix?
Let:
- Target ELRL: n1
- Related source languages: n2, n3, ..., nN
- High-resource language: H
To train H → n1, we mix:
H → n1
n2 → n1
n3 → n1
...
nN → n1
Key design choices:
- Remove explicit source language identifiers
- Force implicit structural transfer
- Preserve decoder specialization
Unlike naïve multilingual mixing, SrcMix prevents decoder fragmentation
and improves performance under extreme data scarcity.
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## 🧡 First Public Angika MT Dataset
This work introduces the **first publicly available machine translation
training and evaluation dataset for Angika**, an Indo-Aryan language
spoken in eastern India.
Dataset available here:
huggingface.co
The dataset includes:
- Parallel training data
- Evaluation splits
- FLORES-aligned dev/test sets
- Clean preprocessing for reproducibility
- …