FRED as an Event Extraction Tool.
Aldo Gangemi, Ehab Hassan, Valentina Presutti, Diego Reforgiato Recupero · 2013
Events are elusive entities; as the authors of [7] argue, even human annotators do not agree on what is an event and what is its boundary in terms of the extension of its participants, temporal and geospatial extent, etc. More aspects of events appear when trying to recognize or extract them from text: polarity of speaker’s judgment on events, negation, modality, relations (temporal, causal, declarative, etc.) to other events, etc. For example, the text: The Black Hand might not have decided to barbarously assassinate Franz Ferdinand after he arrived in Sarajevo on June 28th, 1914. expresses three events (decide, assassinate, arrive), with Black Hand being a participant in two of them, Franz Ferdinand in the third (arrive), a temporal extent for the third (June 28th, 1914), and a relative temporal extent for the other two (given the third’s extent and the past tense suffixes in the first and third), a geo-spatial extent (Sarajevo), a judgment with negative polarity on the second event (barbarously), a negation (not) over the modality (might) modifying the first event, and an explicit