Automatic identification of semantic relations in Italian complex nominals

This paper addresses the problem of the identification of the semantic relations in Italian complex nominals (CNs) of the type N+P+N. We exploit the fact that the semantic relation, which is underspecified in most cases, is partially made explicit by the preposition. We develop an annotation framework around five different semantic relations, which we use to create a corpus of 1700 Italian CNs, obtaining an inter-annotator agreement of K=.695. Exploiting this data, for each preposition p we train a classifier to assign one of the five semantic relations to any CN of the type N+p+N, by using both string and supersense features. To obtain supersenses, we experiment with a sequential tagger as well as a plain lookup in MultiWordNet, and find that using information obtained from the former yields better results.