Desperately Seeking Implicit Arguments in Text.

In this paper, we address the issue of automatically identifying null instantiated arguments in text. We refer to Fillmore's theory of pragmatically controlled zero anaphora (Fillmore, 1986), which accounts for the phenomenon of omissible arguments using a lexically-based approach, and we propose a strategy for identifying implicit arguments in a text and finding their antecedents, given the overtly expressed semantic roles in the form of frame elements. To this purpose, we primarily rely on linguistic knowledge enriched with role frequency information collected from a training corpus. We evaluate our approach using the test set developed for the SemEval task 10 and we highlight some issues of our approach. Besides, we also point out some open problems related to the task definition and to the general phenomenon of null instantiated arguments, which needs to be better investigated and described in order to be captured from a computational point of view.