Opera Graeca Adnotata: Building a 34M+ Token Multilayer Corpus for Ancient Greek

TL;DR

Opera Graeca Adnotata is a comprehensive, multilayer annotated corpus of over 34 million tokens of Ancient Greek texts, integrating multiple annotation layers for linguistic analysis and research.

Contribution

This work introduces the largest open-access multilayer corpus for Ancient Greek, with detailed annotations and scalable formats, enabling advanced linguistic and computational studies.

Findings

Largest open-access Ancient Greek corpus with 34M+ tokens

Seven detailed annotation layers including syntax and morphology

Rule-based and parser-based annotation methods used

Abstract

In this article, the beta version 0.1.0 of Opera Graeca Adnotata (OGA), the largest open-access multilayer corpus for Ancient Greek (AG) is presented. OGA consists of 1,687 literary works and 34M+ tokens coming from the PerseusDL and OpenGreekAndLatin GitHub repositories, which host AG texts ranging from about 800 BCE to about 250 CE. The texts have been enriched with seven annotation layers: (i) tokenization layer; (ii) sentence segmentation layer; (iii) lemmatization layer; (iv) morphological layer; (v) dependency layer; (vi) dependency function layer; (vii) Canonical Text Services (CTS) citation layer. The creation of each layer is described by highlighting the main technical and annotation-related issues encountered. Tokenization, sentence segmentation, and CTS citation are performed by rule-based algorithms, while morphosyntactic annotation is the output of the COMBO parser trained on the data of the Ancient Greek Dependency Treebank. For the sake of scalability and reusability, the corpus is released in the standoff formats PAULA XML and its offspring LAULA XML.