However, identifying potential arguments (which is typically performed by an entity extraction system), linking arguments to their event mentions (which is typically performed by an event extraction system), and determining the compatibility between two event arguments (which is the job of an entity coreference resolver), are all non-trivial tasks.
end-to-end event coreference resolution is complicated in part by the fact that an event coreference resolver has to rely on the noisy outputs produced by its upstream components in the standard information extraction (IE) pipeline.