Existing event extraction work often heavily relies on a rich set of hand-designed features and utilizes existing NLP toolkits and resources (Ji and Grishman, 2008;Patwardhan and Riloff, 2009;Liao and Grishman, 2010;McClosky et al., 2011;Huang and Riloff, 2012;Li et al., 2013a;Li et al., 2013b;Li et al., 2014).
it is often challenging to adapt prior methods to multi-lingual or non-English settings since they require extensive linguistic knowledge for feature engineering and mature NLP toolkits for extracting the features without severe error propagation.