A Multi-Phase Approach to Biomedical Event Extraction

In this paper, we propose a system for biomedical event extraction using multi-phase approach. It consists of event trigger detector, event type classifier, and relation recognizer and event compositor. The system firstly identifies triggers in a given sentence. Then, it classifies the triggers into one of nine predefined classes. Lastly, the system examines each trigger whether it has a relation with participant candidates, and composites events with the extracted relations. The official score of the proposed system recorded 61.65 precision, 9.40 recall and 16.31 f-score in approximate span matching. However, we found that the threshold tuning for the third phase had negative effect. Without the threshold tuning, the system showed 55.32 precision, 16.18 recall and 25.04 f-score.