Towards a Computational Model of Anaphora in Discourse: Reference to Events and Actions

When people talk or write, they refer to things, objects, events, actions, facts and/or states that have been mentioned before. Such context-dependent reference is called anaphora. In general, linguists and researchers working in artificial intelligence have looked at the problem of anaphora interpretation as that one of finding the correct antecedent for anaphor - that is, the previous words or phrases to which the anaphor is linked. Lately, people working in the area of anaphora have suggested that in order for anaphors to be interpreted correctly, they must be interpreted by reference to entities evoked by the previous discourse rather than in terms of their antecedents. In this recent work, people have focused on entities of type concrete individual (an x) or set of such individuals (some xs) or generic class of such individuals (xs). This proposal focuses on anaphora interpreted as referring to entities of type event and action. It considers four issues: (i) what aspects of the discourse give evidence of the events and actions the speaker is talking about, (ii) how actions and events are represented in the listener\u27s discourse model, (iii) how to delimit the set of events and actions which correspond to possible choices for a particular anaphor, and (iv) how to obtain the speaker\u27s intended referent to an action or event from that set of possible choices. Anaphoric forms that are used to refer to entities of type action and event include sentential-it, sentential-that pronominalizations as well as do it, do that, and do this forms. I will concentrate on the four previously mentioned issues along with other mechanisms that will provide us with better tools for the successful interpretation of anaphoric reference in discourse