---
language:
- grc
license: other
task_categories:
- text-generation
- token-classification
tags:
- ancient-greek
- vowel-length
- macronization
- classics
pretty_name: OGA Macronized (Ancient Greek Vowel Length)
size_categories:
- 1M<n<10M
---

# OGA Macronized

Automatically macronized Ancient Greek text: the phonemic length of the three
"dichrona" (ambiguous-length letters) — alpha (α), iota (ι), upsilon (υ) — has
been marked wherever the [grc-macronizer](https://github.com/Urdatorn/grc-macronizer)
rule-based system could disambiguate it with confidence. A trailing `^` marks a
short dichronon, a trailing `_` marks a long one; dichrona the macronizer could
not resolve are left unmarked (never guessed).

## Source

Text is the [Opera Graeca Adnotata](https://doi.org/10.5281/zenodo.14206061)
corpus (Celano 2024) — ~40M tokens of Ancient Greek aggregating First1KGreek,
the Patristic Text Archive, and Perseus' canonical-greekLit, with lemma/POS/
morphology already annotated by Celano's own parser. That existing annotation
was converted directly into the macronizer's internal representation (bypassing
any separate NLP pipeline) and run through the rule-based macronizer.

- 2,234,599 sentences
- Overall dichrona-in-open-syllables macronization ratio: 69.20%
  (11,627,591 / 16,802,080 disambiguated)

## Fields

- `macronized`: the sentence with `^`/`_` markup, e.g. `χρὴ γι^νώσκειν ὅτι^ πά_σης τῆς γῆς`
- `plain`: the same sentence with markup stripped (i.e. ordinary Greek orthography)

## Intended use

Training data for sequence models that predict Ancient Greek vowel length
(e.g. a char-level tagger), and as an intermediate resource for downstream
prosody-aware NLP (verse scansion, metrical classification, morphology
disambiguation of the dichrona-bearing minimal pairs like ἄν/ἂν).

Note: labels are *silver*, not gold — they come from a rule-based system that
is deliberately conservative (does not guess), not from human annotation. For
gold-standard evaluation, see
[Norma Syllabarum Graecarum](https://github.com/Urdatorn/norma-syllabarum-graecarum).

## License

The underlying OGA corpus is distributed by its authors under the terms shown
on its [Zenodo record](https://doi.org/10.5281/zenodo.14206061); check that
record for the authoritative license before redistribution. The macronization
itself is produced by software licensed under GNU GPL v3
([grc-macronizer](https://github.com/Urdatorn/grc-macronizer)).

## Citation

> Giuseppe G. A. Celano. Opera Graeca Adnotata: Building a 34M+ Token Multilayer Corpus for Ancient Greek. arXiv:2404.00739.

> Thörn Cleland, Albin and Eric Cullhed (forthcoming). Automatic Annotation of Ancient Greek Vowel Length.