Keyphrases
- question answering
- natural language processing
- information retrieval
- information extraction
- natural language
- qa clef
- passage retrieval
- natural language questions
- question classification
- syntactic information
- relation extraction
- cross language
- named entities
- question answering systems
- qa systems
- sentence retrieval
- information retrieval systems
- text mining
- answer validation
- open domain question answering
- data mining
- co occurrence