Employing Two Question Answering Systems in TREC 2005

In 2005, the TREC QA track had two separate tasks: the main task and the relationship task. To participate in TREC 2005 we employed two different QA systems. PowerAnswer-2 was used in the main task, whereas PALANTIR was used for the relationship questions. For the main task, new this year is the use of events as targets in addition to the nominal concepts used last year. Event targets ranged from a nominal event such as “Preakness 1998” to a description of an event as in “Plane clips cable wires in Italian resort”. There were 17 event targets total. Unlike nominal targets, which most often act as the topic of the subsequent questions, events provide a context for the questions. Therefore, targets representing events had questions that asked about participants in the event, about characteristics of the vent and furthermore, had temporal constraints. Also many questions referred to answers of previous questions. To complicate matters, several answers could be candidate for the anaphors used in follow-up questions, but salience mattered. This introduced new complexities for the coreference resolution. Consider the following example: