Unsupervised event extraction

1. A system, comprising:

a memory that stores computer executable components;

a processor that executes the computer executable components stored in the memory, wherein the computer executable components comprise:

a parsing component that identifies candidate event components included in a corpus of unstructured text data using one or more unsupervised machine learning processes; and

an event extraction component that generates structured event information defining different events represented in the corpus of unstructured text data based on the candidate event components.

2. The system of claim 1 , wherein the structured event information defines respective events of the different events using a trigger term, one or more argument terms, one or more roles of the arguments and an event type.

3. The system of claim 1 , wherein the candidate event components comprise candidate event trigger terms and candidate event arguments respectively associated with the candidate event trigger terms.

4. The system of claim 1 , wherein the computer executable components further comprise:

an event representation component that generates event representations using graph embeddings based on the candidate event components.

5. The system of claim 4 , wherein the candidate event components comprise candidate event trigger terms and candidate event arguments respectively associated with the candidate event trigger terms, and wherein the event representations comprise an event representation for each of the candidate event trigger terms.

6. The system of claim 4 , wherein the computer executable components further comprise:

a clustering component that employs the event representations to cluster the candidate event components into different event types.

7. The system of claim 6 , wherein the event extraction component generates the structured event information based on the different event types and the candidate event components respectively grouped with the different event types.

8. The system of claim 6 , wherein the candidate event components comprise candidate event trigger terms and candidate event arguments respectively associated with the candidate event trigger terms, and wherein the computer executable components further comprise:

a role labeling component that labels the candidate event arguments with one or more role attributes representative of roles the candidate event arguments play with respect to the different event types, wherein the event extraction component generates the structured event information based on the different event types, the candidate event trigger terms respectively associated with the different event types, the candidate event arguments respectively associated with the candidate event trigger terms, and the role attributes.

9. The system of claim 8 , wherein the role labeling component employs one or more external knowledge bases to facilitate labeling the candidate event arguments with the one or more role attributes.

10. The system of claim 1 , wherein the unsupervised machine learning processes comprise abstract meaning representation parsing.

11. The system of claim 3 , wherein the computer executable components further comprise:

a role labeling component that employs external knowledge bases to label the candidate event arguments with role attributes representative of one or more roles the candidate event arguments play with respect to the candidate event trigger terms.

12. The system of claim 1 , wherein the computer executable components further comprise:

a query component that receives a query request regarding an event and employs the structured event information to identify parts of the unstructured text data that are relevant to the query request.

13. A method, comprising:

identifying, by a system operatively coupled to a processor candidate event components included in a corpus of unstructured text data using unsupervised machine learning processes; and

generating, by the system, structured event information defining different events represented in the corpus of unstructured text data based on the candidate event components.

14. The method of claim 13 , wherein the candidate event components comprise candidate event trigger terms and candidate event arguments respectively associated with the candidate event trigger terms.

15. The method of claim 13 , further comprising:

generating, by the system, different event representations based on the candidate event components and using graph embeddings.

16. The method of claim 15 , further comprising:

employing, by the system, the different event representations to cluster the candidate event components into different event types.

17. The method of claim 16 , wherein the candidate event components comprise candidate event trigger terms and candidate event arguments respectively associated with the candidate event trigger terms, and wherein the method further comprises:

labeling, by the system, the candidate event arguments with role attributes representative of roles the candidate event arguments play with respect to the different event types, and wherein the generating comprises generating the structured event information based on the different event types, the candidate event trigger terms respectively associated with the different event types, the candidate event arguments respectively associated with the candidate event trigger terms, and the role attributes.

18. The method of claim 13 , wherein the one or more unsupervised machine learning processes comprise abstract meaning representation parsing.

19. A computer program product for unsupervised event extraction, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processing component to cause the processing component to:

identify candidate event components included in a corpus of unstructured text data using unsupervised machine learning processes; and

generate structured event information defining different events represented in the corpus of unstructured text data based on the candidate event components.

20. The computer program product of claim 19 , wherein the candidate event components comprise candidate event trigger terms and candidate event arguments respectively associated with the candidate event trigger terms, and wherein the program instructions executable further cause the processing component to:

generate event representations based on the candidate event trigger terms and the candidate event arguments using graph embeddings;

employ the event representations to cluster the event representations into different event types;

label the candidate event arguments with role attributes representative of one or more roles the candidate event arguments play with respect to the different event types; and

generate the structured event information based on the different event types, the candidate event trigger terms respectively associated with the different event types, the candidate event arguments respectively associated with the candidate event trigger terms, and the one or more role attributes.