Keyphrases
- question answering
- information retrieval
- qa systems
- information extraction
- question answering systems
- cross language
- test collection
- natural language processing
- natural language
- question classification
- qa clef
- open domain
- natural language questions
- passage retrieval
- open domain question answering
- data sets
- artificial intelligence
- answer extraction
- digital libraries
- search engine
- answer validation