Document Level Time-anchoring for TimeLine Extraction

Abstract

This paper investigates the contribution of document level processing of timeanchors for TimeLine event extraction. We developed and tested two different systems. The first one is a baseline system that captures explicit time-anchors. The second one extends the baseline system by also capturing implicit time relations. We have evaluated both approaches in the SemEval 2015 task 4 TimeLine: CrossDocument Event Ordering. We empirically demonstrate that the document-based approach obtains a much more complete time anchoring. Moreover, this approach almost doubles the performance of the systems that participated in the task.