Keyphrases
- question answering
- passage retrieval
- information retrieval
- information extraction
- question answering systems
- answer extraction
- natural language processing
- sentence retrieval
- question classification
- qa clef
- natural language questions
- natural language
- relevance feedback
- document retrieval
- query expansion
- retrieval model
- cross language
- syntactic information
- information retrieval systems
- automatic extraction
- relation extraction
- named entities
- test collection
- image retrieval
- retrieval systems
- language model
- artificial intelligence