Modelling and Publishing the Lexicon der indogermanischen Verben as Linked Open Data
Authors: Valeria Irene Boano, Francesco Mambrini, Marco Carlo Passarotti, Riccardo Ginevra (Università Cattolica del Sacro Cuore, 2023)
Topic: Latin Resources

Abstract
This paper describes the modelling and publication of part of the etymological information in the Lexicon der indogermanischen Verben, an etymological dictionary of verbs attested in ancient Indo-European languages, as Linguistic Linked Open Data. The lexicon has been made interoperable with a set of lexical and textual linguistic resources for Latin in the Lila Knowledge Base.

Introduction
Over the past decades, several linguistic resources for historical languages have become available in digital format. This has given scholars the chance to access and exploit them in a quicker and deeper way. In particular, several different linguistic resources are available for Latin today. They consist of textual corpora, such as the LASLA corpus for Classical Latin and the Index Thomisticus Treebank for Medieval Latin, and lexical resources, like the Lewis and Short dictionary and the Logeion metadictionary. Due to the centuries-long lexicographic tradition for the Latin language, its lexical resources comprise a number of etymological dictionaries. A dictionary is defined as etymological when it contains information about the etymology of its entries, that is about their origin and historical development: for Indo-European (IE) languages, etymological dictionaries often put their entries in relation with reconstructed Proto-Indo-European (PIE) roots, minimal lexical units to which the dictionary’s entry and further related formations may be traced back. It is also often explained by which morphological processes the attested word has been formed from the root. Even if the available resources (for Latin and beyond) provide a huge amount of linguistic information, at the present day, their full exploitation is still hindered by their isolation. In fact, most resources can be accessed only individually, and cannot interact. Isolation of resources is an issue because each resource can really reach its potential only when it is made interoperable with other (types of) resources. Today, interoperability between linguistic resources can be obtained by describing and publishing their data according to the principles of the Linked Open Data paradigm. As a consequence, in recent years, the amount of linguistic resources published as Linked Open Data has been raised substantially, as witnessed by the growing size of the Linguistic Linked Open Data Cloud (LLOD Cloud). In particular, the LiLa Knowledge Base represents a successful example of Linked Open Data (LOD) principles applied to linguistic resources for Latin. Although LiLa currently makes quite a number of linguistic resources for Latin interoperable, there is still a large set of digitized materials to interlink in the Knowledge Base. Among them is an important etymological dictionary, the Lexicon der indogermanischen Verben (LIV). This paper describes the process of transforming information contained in this dictionary into a LLOD resource, linked to LiLa. Section 2 describes the LiLa architecture and the LIV structure. Section 3 details the modelling of the resource, and the linking process. Section 4 describes some possible examples of exploitation and interaction. Finally, Section 5 discusses conclusions and sketches the future work.

Conclusion
Linking a set of data from the LIV to LiLa enhances the Knowledge Base with etymological information about the processes that, starting from PIE roots, have led to the formation of the Latin word forms. Given the highly lexically-based nature of the architecture of the Knowledge Base, this makes the linking of the LIV an important achievement of the LiLa project. The information provided by the LIV is now interoperable with that of the several other lexical resources currently interlinked through LiLa and can be queried together with the textual data provided by the Latin corpora published in the Knowledge Base. In collecting and publishing as LOD the wealth of different digital resources for Latin built so far, an important challenge is to impact the scholarly community that has long been using the data provided today by these resources. The web-based interoperability among resources permitted by the LiLa Knowledge Base makes it possible to exploit such wealth of (meta)data like never before, in terms both of the quantity of the (meta)data under analysis and of the quality of the process leading to their retrieval. Interlinking through the Knowledge Base a set of data from the LIV, a reference lexical resource for the communities of Classicists and Historical Linguists, is expected to help overcome the challenge of making the use of LiLa a daily presence in the life of scholars who work in the fields of Classics and Historical Linguistics. Finally, it is worth considering that the LIV provides etymological information not only about the Latin word forms, but, for each PIE root, it also reports a set of word forms which reflect the same root in several other IE daughter languages. The availability of this information allows for substantial research work to be performed in the near future. Indeed, by applying the principles of the Linked Data paradigm and reusing the same vocabularies adopted in LiLa to interlink the distributed linguistic resources for Latin, it is now possible to move one step further from the Latin language and aim to make interoperable word forms from several IE languages, by using the collection of PIE roots provided by the LIV as a kind of pivot resource to interlink them all.