Cross-Document Event Coreference: Annotations, Experiments, And Observations

We have developed cross document event tracking technology that extends our earlier efforts in cross document person coreference. The software takes class of events, like "resignations" and clusters documents tha t mention resignations into equivalence classes. Documents belong to the same equivalence class if they mention the same "resignation" event, i.e. resignations involving the same person, time, and organization. Other events evaluated include "elections" and "espionage" events. Results range from 45-90% F-measure scores and we present a brief interannotator study for the "elections" data set.