Risorse e strumenti per le varietà storiche dell'italiano: il progetto TrAVaSI
Authors: Manuel Favaro, Marco Biffi, Simonetta Montemagni (CNR-ILC, Università di Firenze, 2020)
Topic: Lexical and Semantic Resources and Analysis

Abstract
This contribution aims to present the project TRAVaSI (Automatic Treatment of Historical Varieties of Italian), whose objective is the creation of resources for the automatic treatment of historical varieties of the Italian language, in particular diacronic lexics and corpora enriched with linguistic annotation to be used for the development and/or specialization of annotation tools. The contribution sets out the objectives, the first results achieved and the development prospects.

Introduction
There are now numerous digital text files that testify to historical varieties of Italian. However, access and questioning of texts are often elementary, mostly limited to the strings of characters that make up the text; this complicates the work of scholars and makes it almost impossible for non-experts to use resources. This situation shows that, despite recent progress in the field of Digital Humanities, the access and questioning of texts that testify historical varieties of Italian, more or less distant in time, still represent a challenge today. The project TRAVaSI (Automatic Treatment of Historical Varieties of Italian), born from the collaboration between the Institute of Computational Linguistics "Antonio Zampolli" and the Accademia della Crusca and funded by the Tuscany Region, aims to face this challenge, creating the prerequisites for navigation and the systematic questioning of sources that document the historical varieties of the language. The starting point of the project is pragmatic: to strengthen two instruments made by the Accademia della Crusca within other projects. The tools in question are the electronic version of the Grand Dictionary of Italian Language (GDLI) 1 and the database of the Dynamic Vocabulary of Modern Italian, which is more precisely the specific object of investigation of the contribution that we present here. TRAVaSI has as its main objective to maximize practical implementations, but projecting them in the framework of the development of reference tools for diacronically connotationd databases and historical dictionaries in electronic version. In particular, it is a question of exploiting the opportunity to work at the same time (and therefore to intersect researches, results and partial products) on the one hand on the structuring and marking of a historical dictionary such as the GDLI in its computerized version (by developing semi-automatic collation procedures of the text obtained with the OCR and marking of the identified structural fields; see Sassolini et alii 2019, Biffi and Sassolini 2020), and on the other on the creation of computational lexicons differentiated in diacronym to finally cover the weakening even to the zero degree of the effectiveness of linguistic annotation tools when we depart from the ideal conditions of contemporary Italian written those varieties substantially attributable to the sample of the Lexicon of frequency of contemporary Italian (LIF). And thus determine an enlargement of the effectiveness of the linguistic annotation tools in diacronia, diamesia and diaphasia. On the humanistic side, the developments of these instruments have considerable repercussions, both in the perspective of giving scholars methods of investigation increasingly powerful for their linguistic research, and in that, dear to an institution like the Accademia della Crusca, to reach a wider user. The digitization of the texts and their availability on the network are not enough to bring a user not limited to those involved in the work of the cultural heritage handed down. In order to make the contents of cultural institutions accessible to a wide and varied audience, it is necessary to offer ways of access and navigation equipped with linguistic intelligence. To date, it is widely recognized that the application of methods and techniques for the Automatic Treatment of Language (TAL) to historical varieties of a language presents innumerable obstacles, since the tools developed for modern languages require specializations at various levels (lexical, morphological and syntactical) to be successfully used in the treatment of primary sources that represent the basis of humanistic studies. For the Italian language, Pennacchiotti and Zanzotto (2008) report the results of an exploratory study on the difficulties resulting from the automatic treatment of historical varieties of the Italian language based on a diacronic corpus that collects literary Italian texts (both prose and poetry) from 1200 to the end of the nineteenth century: the analyses, focused on the composition of the vocabulary and on the morphological and morpho-syntactic annotation, confirm that the automatic treatment of historical varieties of the Italian language is an open challenge. One of the challenges that the TRAVaSI project intends to face. In this area, the project revolves around two main directions, concerning the construction of corpora enriched with linguistic information to be used for the evaluation and/or training of annotation tools, and diacronic computational lexicons able to support the process of lemmatization of the text. At the moment, the linguistic annotation of the texts concerns the morpho-syntactic level. The resources developed on both fronts will be integrated into existing research infrastructures (e.g. CLARIN-IT) in order to increase their visibility, accessibility and interoperability with similar resources. On the linguistic-computational side, the design and construction of resources and tools for the variety of use of the language that differ to a different extent from the contemporary Italian written on which the TAL instruments are typically trained constitutes a fertile field of experimentation for the development and refinement of innovative technologies of TAL. The article illustrates the methodology defined for the construction of resources and the first results achieved. Section 2 describes the diacronic corpus selected for the annotation, and Section 3 illustrates the method followed for the annotation of the corpus. Section 4 reports and discusses the results of the first semi-automatic annotation experiments and the review strategy developed. Section 5 illustrates the automatic annotation results achieved with existing annotation systems for contemporary Italian; finally, Section 6 outlines current and future developments.

Conclusion
We briefly illustrated the steps that the TRAVaSI project is following to build resources for the automatic treatment of historical Italian varieties, differentiated also in diaphasia, diaphasia and at textual level. In this preliminary phase we have tried to give answers to unsolved questions about the annotation and lemmatization of Italian in diacronia, for example on how to treat some forms (diversbate voices, infinite nouns, regional variants, to cite some examples) and on the criteria of lemmatization of the phono-morphological variants of the same lemma. The resources developed will be exploited to test existing instruments of morpho-syntactic annotation and lemmatization and for the development and/or specialization of software components for the treatment of historical varieties of the Italian language. The first results collected from the analysis of the VoDIM subcorpus selected clearly show that the dimensions of variation to be taken into account are multiple and strongly interrelated, deriving from different types of processes, such as the variation over time (diaconic variation), the variation related to sociolinguistic variables or linked to the textual genre or to the style of the writer. The places of variation range from spelling, morphology and syntax (especially in diacronya and texts of specialist domains). This type of analysis is fundamental in order to define a methodology for the creation of additional resources, with the aim of progressively widening the chronological arc but also the type of variety of use of the language in order to be able to build TAL instruments that are applicable to Italian texts of the previous centuries, attributable to different varieties of use of the language. From this perspective, the corpus selected as the starting point of the TRAVaSI project becomes particularly significant as it creates the prerequisites for the definition of a method for the specialization of annotation tools in relation to multiple linguistic, diacronic but also diaphasic, diastatic or corresponding to textual types. The current developments include: 1. training and specialization of UDPipe models by means of a test set consisting of the test corpus domains, on which, from time to time, the increase in accuracy of the annotation will be evaluated; 2. the construction of diacronic lexicons starting from annotated corporas starting from VoDIM and subsequently drawing from chronologically pre-existing resources as the basis for the lemmatization process; 3. on the basis of the distance between the corpus used for training and the texts to be analyzed, the identification of the most appropriate linguistic model to be used for linguistic annotation.