# An Event Extraction Approach Based on a Multi-Round Q&A Framework
## 3 Models
### The Construction Method of Question Templates in a Multi-Round Q&A Framework  
In the multi-round Q&A process of this paper, the construction of questions is a key step, and questions that fully incorporate a priori information help to enhance learning to more semantic information. Before defining the questions, this paper analyzed the ACE2005 dataset [18], which consists of 8 event types and 33 subtypes. Within each event type, a set of potential participant roles is included for entities that appear within its paradigm. In some cases, the question of whether a potential event is taggable depends on the presence of entities that populate certain roles. Among the event argument elements, there are  
Figure 1: The overall framework of the model. Figure 2: Complete multi-round flow for event extraction. two main categories of argument elements: event participants and event attributes. An event participant is a markable entity that participates in some way in an event in a certain class of events. For example, <Person> in a marriage event <Marry>; <Agent>, <Victim>, <Instrument> in a death event <Die>; and so on. Event attributes are attributes associated with events other than participants, such as <Time>, <Place>, <Position>, and so on. Table 1 shows the event types and parameters in the ACE2005 dataset. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Event Type** & **Type** & **Event Role** \\ \hline \multirow{4}{*}{Life} & Be-Born & person, time, place \\ \cline{2-3}  & Marry & person, time, place \\ \cline{2-3}  & Divorce & person, time, place \\ \cline{2-3}  & Injure & time, place, agent, victim, instrument \\ \cline{2-3}  & Die & time, place, agent, victim, instrument \\ \hline Movement & Transport & time, transporter, artifact, vehicle, price, origin, destination \\ \hline \multirow{2}{*}{Transaction} & Transfer-Ownership & time, place, buyer, seller, beneficiary, artifact, price \\ \cline{2-3}  & Transfer-Money & time, place, giver, recipient, beneficiary \\ \hline \multirow{4}{*}{Business} & Start-Org & time, place, agent, org \\ \cline{2-3}  & Merge-Org & time, place, org \\ \cline{2-3}  & Declare-Bankruptcy & time, place, org \\ \cline{2-3}  & End-Org & time, place, org \\ \hline \multirow{4}{*}{Conflict} & Attack & time, place, attacker, target, instrument \\ \cline{2-3}  & Demonstrate & time, place, entity \\ \hline \multirow{4}{*}{Contact} & Meeting & time, place, entity, duration \\ \cline{2-3}  & Phone-Write & time, entity \\ \hline \multirow{4}{*}{Personnel} & Start-Position & person, time, place, entity, position \\ \cline{2-3}  & End-Position & person, time, place, entity, position \\ \cline{2-3}  & Nominate & person, time, place, agent, position \\ \cline{2-3}  & Elect & person, time, place, agent, position \\ \hline \multirow{4}{*}{Personnel} & Arrest-Jail & person, time, place, agent, crime \\ \cline{2-3}  & Release-Parole & person, time, place, entity, crime \\ \cline{2-3}  & Trial-Hearing & time, place, defendant, prosecutor, adjudicator, crime \\ \cline{2-3}  & Charge-Indict & time, place, defendant, prosecutor, adjudicator, crime \\ \cline{2-3}  & Sue & time, place, defendant, adjudicator, crime, plaintiff \\ \cline{2-3}  & Convict & time, place, defendant, adjudicator, crime \\ \cline{2-3}  & Sentence & time, place, defendant, adjudicator, crime, sentence \\ \cline{2-3}  & Fine & time, place, entity, adjudicator, crime, money \\ \hline \multirow{4}{*}{Justice} & Execute & person, time, place, agent, crime \\ \cline{2-3}  & Extradite & person, time, agent, crime, destination, origin \\ \cline{2-3}  & Acquit & time, place, defendant, adjudicator, crime \\ \hline \multirow{4}{*}{Justice} & Pardon & time, place, defendant, adjudicator, crime \\ \cline{2-3}  & Appeal & time, place, defendant, adjudicator, crime, prosecutor \\ \hline \end{tabular}
\end{table} 
Table 1: Event types and parameters in ACE2005 dataset. The \"wh-\" question word used in the question template is defined according to the different attributes of the argument, and the question is constructed using the [wh_word].