70 likes | 191 Views
Hierarchical Name Entity Recognition. Motivation. Traditional NER assume that each entity type is an independent class. However, they can have a hierarchical structure. Genia Corpus. Models. All models are based on MEMM classifier Model 1 Just take the ancestor types to be features
E N D
Motivation • Traditional NER assume that each entity type is an independent class. • However, they can have a hierarchical structure
Models • All models are based on MEMM classifier • Model 1 • Just take the ancestor types to be features • Model 2 • Train a classifier at each level • Do verterbi on paths in the tree
Model 3 • Every node in the tree has a local weight and global weight • Global weight is for classification. • The sum of the local weights from the root to the node • Example
Acknowledgement • Thanks David and Mihai for insightful discussions • Thanks instructors for excellent courses • Thanks TAs for hard work.