Creating Hierarchical Relations in a Multilingual Event-type Ontology

AbstractThis paper describes the work on hierarchization of the SynSemClass event-type ontology. The original resource has been extended by a hierarchical structure to model specialization and generalization relations between classes that are formally and technically unrelated in the original ontology. The goal is to enable one to use the ontology enriched by the hierarchical concepts for annotation of running texts in symbolic meaning representations, such as UMR or PDT. The hierarchy is in principle built bottom-up, based on existing SSC classes (concepts). This approach differs from other approaches to semantic classes, such as in WordNet or VerbNet. Although the hierarchical relations are similar, the underlying nodes in the hierarchy are not. In this paper, we describe the challenges related to the principles chosen: single-tree constraint and finding features for the definitions of specificity/generality. Also, a pilot inter-annotator experiment is described that shows the difficulty of the hierarchization task.