Zero-Shot Transfer Learning for Event Extraction
Table 6: Performance on Various Types Using Justice Subtypes for Training
['Type', 'Subtype', 'Hit@k Trigger Classification 1', 'Hit@k Trigger Classification 3', 'Hit@k Trigger Classification 5']
We further evaluate the performance of our transfer approach on similar and distinct unseen types. The 33 sub-types defined in ACE fall within 8 coarse-grained main types, such as Life, Justice. Each subtype belongs to one main type. Subtypes that belong to the same main type tend to have similar structures. For example, Trial-Hearing and Charge-Indict have the same set of argument roles. For training our transfer model, we select 4 subtypes of Justice: Arrest-Jail, Convict, Charge-Indict, Execute. For testing, we select another 3 subtypes of Justice: Sentence, Appeal, Release-Parole. Additionally, we also select one subtype from each of the other seven main types for comparison.