The Annotation of Thematic Structure and Alternations face to the Semantic Variation of Action Verbs. Current Trends in the IMAGACT Ontology.

We present some issues in the development of the semantic annotation of IMAGACT, a multimodal and multilingual ontology of actions. The resource is structured on action concepts that are meant to be cognitive entities and to which a linguistic caption is attached. For each of these concepts, we annotate the minimal thematic structure of the caption and the possible argument alternations allowed. We present some insights on this process with regard to the notion of thematic structure and the relationship between action concepts and linguistic expressions. From the empirical evidence provided by the annotation process, we discuss the very nature of thematic structure, arguing that it is neither a property of the verb itself nor a property of action concepts. We further show what is the relation between thematic structure and 1- the semantic variation of action verbs; 2- the lexical variation of action concepts.