---
license: cc-by-sa-4.0
task_categories:
  - token-classification
task_ids:
  - parsing
  - part-of-speech
  - lemmatization
language:
  - vi
annotations_creators:
  - machine-generated
language_creators:
  - found
multilinguality:
  - monolingual
source_datasets:
  - undertheseanlp/UTS_VLC
  - undertheseanlp/UVN-1
size_categories:
  - 10K<n<100K
tags:
  - universal-dependencies
  - vietnamese
  - nlp
  - dependency-parsing
  - pos-tagging
---

# UDD-1: Universal Dependency Dataset for Vietnamese

## Dataset Description

Vietnamese Universal Dependency dataset created by Underthesea NLP. This dataset follows the [Universal Dependencies](https://universaldependencies.org/) annotation guidelines.

### Dataset Summary

- **Language:** Vietnamese (vi)
- **Version:** 1.1
- **Domains:** ⚖️ Legal (Laws) + 📰 News
- **Total Sentences:** 20,000
- **Total Tokens:** ~453,551
- **Annotation:** Machine-generated using Underthesea NLP toolkit

### Data Sources

| Source | Domain | Sentences | Tokens |
|--------|--------|----------:|-------:|
| [UTS_VLC](https://huggingface.co/datasets/undertheseanlp/UTS_VLC) | ⚖️ Legal | 10,000 | ~230,709 |
| [UVN-1](https://huggingface.co/datasets/undertheseanlp/UVN-1) | 📰 News | 10,000 | ~222,842 |
| **Total** | | **20,000** | **~453,551** |

### Data Splits

Following [UD guidelines](https://universaldependencies.org/contributing/repository_files.html):

| Split | Sentences | Percentage |
|-------|----------:|-----------:|
| Train | 18,282 | 91.4% |
| Validation | 859 | 4.3% |
| Test | 859 | 4.3% |
| **Total** | **20,000** | **100%** |

## Usage

```python
from datasets import load_dataset

# Load all splits
dataset = load_dataset("undertheseanlp/UDD-1")
print(dataset)

# Access specific split
train_data = dataset["train"]
dev_data = dataset["validation"]
test_data = dataset["test"]

# Example sentence
print(train_data[0])
```

### Sentence ID Prefixes

- `s*` - Sentences from legal corpus (UTS_VLC)
- `uvn-*` - Sentences from news corpus (UVN-1)

## Fields

| Field | Description |
|-------|-------------|
| `sent_id` | Sentence identifier |
| `text` | Original sentence text |
| `tokens` | Word tokens |
| `lemmas` | Lemmatized forms |
| `upos` | Universal POS tags |
| `xpos` | Language-specific POS tags |
| `feats` | Morphological features |
| `head` | Head token indices (1-indexed, 0=root) |
| `deprel` | Dependency relation labels |
| `deps` | Enhanced dependencies |
| `misc` | Miscellaneous annotations |

## Citation

```bibtex
@misc{underthesea_udd1_2026,
  title = {UDD-1: Universal Dependency Dataset for Vietnamese},
  author = {Underthesea NLP},
  year = {2026},
  publisher = {Hugging Face},
  url = {https://huggingface.co/datasets/undertheseanlp/UDD-1}
}
```

## License

This dataset is licensed under [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).

## Contact

- GitHub: [undertheseanlp/underthesea](https://github.com/undertheseanlp/underthesea)
- Email: anhv.ict91@gmail.com