Keyphrases
- question answering
- open domain
- event extraction
- text summarization
- information extraction
- question answering systems
- natural language processing
- information retrieval
- named entity recognition
- natural language
- relation extraction
- cross language
- passage retrieval
- named entities
- test set
- qa clef
- natural language questions
- semantic role labeling
- word segmentation
- text retrieval
- evaluation methodology