Leveraging FrameNet to Improve Automatic Event Detection

Proceedings of the 54th Annual Meeting of the Association for Computational Linguistics, pages 2134–2143, Berlin, Germany, August 7-12, 2016. c⃝2016 Association for Computational Linguistics Leveraging FrameNet to Improve Automatic Event Detection Shulin Liu, Yubo Chen, Shizhu He, Kang Liu and Jun Zhao National Laboratory of Pattern Recognition Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China {shulin.liu, yubo.chen, shizhu.he, kliu, jzhao}@nlpr.ia.ac.cn Abstract Frames defined in FrameNet (FN) share highly similar structures with events in ACE event extraction program. An even- t in ACE is composed of an event trig- ger and a set of arguments. Analogously, a frame in FN is composed of a lexical u- nit and a set of frame elements, which play similar roles as triggers and arguments of ACE events respectively. Besides having similar structures, many frames in FN ac- tually express certain types of events. The above observations motivate us to explore whether there exists a good mapping from frames to event-types and if it is possible to improve event detection by using FN. In this paper, we propose a global infer- ence approach to detect events in FN. Fur- ther, based on the detected results, we an- alyze possible mappings from frames to event-types. Finally, we improve the per- formance of event detection and achieve a new state-of-the-art result by using the events automatically detected from FN. 1 Introduction In the ACE (Automatic Context Extraction) even- t extraction program, an event is represented as a structure consisting of an event trigger and a set of arguments. This paper tackles with the event de- tection (ED) task, which is a crucial component in the overall task of event extraction. The goal of ED is to identify event triggers and their correspond- ing event types from the given documents. FrameNet (FN) (Baker et al., 1998; Fillmore et al., 2003) is a linguistic resource storing con- siderable information about lexical and predicate- argument semantics. In FN, a frame is defined as a composition of a Lexical Unit (LU) and a set of Frame Elements (FE). Most frames contain a set of exemplars with annotated LUs and FEs (see Figure 2 and Section 2.2 for details). From the above definitions of events and frames, it is not hard to find that the frames defined in FN share highly similar structures as the events defined in ACE. Firstly, the LU of a Frame plays a similar role as the trigger of an event. ACE de- fines the trigger of an event as the word or phrase which most clearly expresses an event occurrence. For example, the following sentence “He died in the hospital.” expresses a Die event, whose trig- ger is the word died. Analogously, the LU of a frame is also the word or phrase which is capa- ble of indicating the occurrence of the expressed semantic frame. For example, the sentence “Aero- planes bombed London.” expresses an Attack1 frame, whose LU is the word bombed. Secondly, the FEs of a frame also play similar roles as …

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