---
license: apache-2.0
---

# Dataset Card for Russian Modern–Pre-Reform Orthography Parallel Corpus

## Dataset Summary
This dataset contains **50,000 parallel text examples** of Russian phrases and sentences, aligned between **modern Russian orthography** (post-1918 spelling reform) and **pre-reform Russian orthography** (as used before the 1918 spelling changes). It is intended for use in training and evaluating models for Russian orthography conversion, historical text processing, and related NLP tasks.

The dataset includes a mix of:
- Short phrases (e.g., *"Мир и порядок"* → *"Мiръ и порядокъ"*)
- Complete sentences with varying syntactic structures, time expressions, and subordinate clauses

## Supported Tasks and Leaderboards
- **Spelling conversion** (modern ↔ pre-reform)
- **Historical text normalization**
- **Parallel corpus training** for machine translation models between orthographic standards

## Languages
- Russian (`ru`)

## Dataset Structure
**Columns**:
- `russian_modern` — modern Russian text (UTF-8)
- `russian_prereform` — pre-reform Russian text (UTF-8)

**Number of rows**: 50,000

**Format**: CSV (UTF-8). Can be converted to Parquet.

## Data Creation
Modern Russian phrases were programmatically generated from a template-based system with a vocabulary of people, actions, objects, places, and time expressions, combined with pre-written natural sentences.  
Pre-reform orthography was produced using a heuristic conversion algorithm, applying common 19th–early 20th century spelling rules:
- Final hard sign (ъ) after hard consonants
- Prepositions *в*, *с* → *въ*, *съ* before consonants
- `і` before vowels/й
- Common lexical substitutions with ѣ (e.g., *вѣтер*, *дѣло*, *лѣс*, *тѣнь*)

## Limitations
- The orthography converter is heuristic and may not match all authentic pre-1918 lexical exceptions.
- Phrases are synthetic, not sourced from historical corpora.
- Not suitable for linguistic studies of authentic pre-reform usage without further manual validation.

## License
Apache 2.0

## Citation
If you use this dataset, please cite as:

```text filename="citation"
@misc{russian_modern_prereform_2025,
  title = {Russian Modern–Pre-Reform Orthography Parallel Corpus},
  year = {2025},
  author = {Kenneth Hamilton},
  howpublished = {\url{https://huggingface.co/datasets/}},
  note = {Parallel corpus of modern and pre-1918 Russian orthography}
}
```