Evaluating Italian Parsing Across Syntactic Formalisms and Annotation Schemes

This paper describes some results about the way syntactic representations and parsing methodologies affect the performance of systems for parsing Italian. Italian has a rich morphology, especially with respect to Verbal suffixes, that can provide a parser with useful information for making the correct choices. With respect to syntactic representation, the experiments are based on a treebank for Italian, which has been delivered both in a dependency and in a constituency formalism, and for each of them also annotated at different degrees of specificity. The two paradigms are compared, and the different degrees of specificity in marking some syntactic phenomena are pointed out. On the basis of this treebank, statistical parsers have been evaluated. The results have shown that both the representation format and the parsing approach strongly affect the performance, that in some cases are very close and in others drastically different from the ones that constitute the state of the art for English.