Keyphrases
- question answering
- information retrieval
- passage retrieval
- question answering systems
- natural language processing
- natural language
- information extraction
- sentence retrieval
- cross language
- answer extraction
- qa clef
- question classification
- named entities
- syntactic information
- natural language questions
- domain knowledge
- knowledge base
- open domain question answering
- answer validation
- relation extraction
- expert systems
- answering questions
- document retrieval
- qa systems
- semantic roles
- retrieval systems
- test collection
- relevance feedback
- image retrieval
- query expansion
- information retrieval systems
- search engine