In this paper, we aim to tackle the situation when the category of eventtype is undefined, and we try to derive the eventtypes from the corpus.
we automatically build an event type paradigm by using a trigger clustering algorithm: 1) we introduce a trigger extraction algorithm based on the dependency syntactic structure; 2) a trigger filter is then constructed to remove some noisy candidate triggers; 3) we develop an event type discovery algorithm based on our proposed trigger clustering methods.