Bootstrapping Enhanced Universal Dependencies for Italian
Authors: Maria Simi, Simonetta Montemagni (Università di Pisa, CNR-ILC, 2018)
Topic: Syntax and Dependency Treebanks

Abstract
The paper presents an extension English. The paper presents an extension of the Italian Universal Dependencies Treebank with an “enhanced” representation level (e-IUDT), aimed at simplifying the information extraction process. The modules developed to semi-automatically build e-IUDT were delexicalized to perform cross-language enhancements: preliminary experiments in this direction led to promising results.

Introduction
Introduction Introduction The Universal Dependencies (UD) project, launched in 2015, aims at developing crosslinguistically consistent treebank annotation for many languages, with the goal of facilitating multilingual parser development, cross-lingual learning, and parsing research from a language typology perspective (Nivre et al., 2016). UD represents an open community effort with over 200 contributors producing more than 100 treebanks in over 60 languages. Starting from the Stanford Dependencies project, from which Universal Dependencies (UD) originate, two syntactic representation options are made available, suited to different use cases (De Marneffe and Manning, 2008): the so-called “basic” representation where a close parallelism to the source text is maintained (i.e. where each word of the original sentence is present as a node), and the so-called “collapsed and propagated” representation which was conceived with a specific view to information extraction tasks. Within the current version of UD, the “collapsed and propagated” representation has evolved into the graph-based enhanced representation proposed by Schuster and Manning (2016). Since UD version 2.2 (officially released on July 2018), “enhanced treebanks” started to appear for a limited number of languages, i.e. English, Finnish, Russian, Polish, Dutch, Latvian. In order to foster the development of enhanced treebanks for other languages, transfer experiments exploiting existing treebanks are reported in the literature, following both rule-based (Schuster and Manning 2016) and data-driven (Nyblom et al., 2013) approaches. This paper describes the approach we used for developing and validating the enhanced version of the Italian UD Treebank and reports the first results of transfer experiments to English. 2 Enhanced dependencies Enhanced dependencies were proposed as a way to simplify the process of information extraction. Enhancements, for the most part, result in additional links added to the dependency tree, motivated by inferences, which remain however anchored at the surface representation level. The result of enhancing a dependency tree is a graph, possibly with cycles, but not necessarily a super graph (since some of the original arcs may be discarded). The current UD guidelines are quite conservative, i.e. they suggest practically feasible enhancements only. Despite this, enhancements cannot always be achieved automatically, and the task is challenging enough to be interesting. Ac-

Conclusion
We extended the Italian UD Treebank with an enhanced representation level: Italian is now among the few languages within UD with a gold enhanced Treebank which will be part of Release v2.3. The modules used to semi-automatically build e-IUDT were delexicalized to carry out cross-language enhancements: preliminary results for both Italian and English are promising. The contribution also includes better and more detailed specifications to the constantly inprogress guidelines. Current developments include: from a mono-lingual perspective, extension of the typology of enhancements; from the multi-lingual perspective, testing and extending the enhancement component successfully used with English for other languages.